[Introduction] [Motion] [Projectile Motion] [Vectors]

[Newton's Laws] [Friction] [Circular Motion] [Gravity]

[Conservation of Energy] [Conservation of Momentum, Collisions] [Statics, Torque]

[Rotation Kinematics and Dynamics] [Fluids] [Temperature, Ideal Gas, Expansion]

[Heat, Thermodynamics, Heat Engines] [Simple Harmonic Motion] [Sound]

Introduction | |

College Physics I Intro To Course | Lecture (7 minutes) This video gives an overview to the topics that will be discussed in these videos. The video also shows how to access the free physics textbook at OpenStaxCollege.org. College Physics I |

OpenStax College Physics Chapter 1 Overview | Lecture (8 minutes) This video gives a quick survey of Chapter 1 of OpenStax College Physics. College Physics I |

Physics Concepts: Metric Units, Converting Units, Significant Figures | Concepts (6 minutes) This video discusses introductory concepts for a physics course. Concepts covered are: metric units, systematic errors, converting units, simple significant figures. |

Conversion of Units | Example (6 minutes) This video shows examples of converting miles to meters, miles/hour to meters/second, and years to seconds. In each case a conversion factor from a book is used and then, in addition, the calculation is done in a more tedious way using basic facts. |

8 Unit Conversion Examples | Example (9 minutes)The conversion of units is a common task in science classes. This video gives eight examples of conversion of units for distance, speed, and time. Most of the conversion examples start with a number with English system units which is then converted to the metric system. |

Cylinder Density Volume Mass | Example (5 minutes) A small, but long, aluminum cylinder is partially inside a larger, but shorter, aluminum cylinder. The total volume of the object is calculated. The mass of the object is calculated. |

Fermi Problem | Example (9 minutes) "Fermi Problems" ask the student to estimate the answer to some question. This Fermi Problem asks for the fraction of the area of the land area of Earth needed for everyone on Earth to stand side-by-side. Often, the correct answer to a Fermi Problem is not known. A general principle is that you should break the problem into many factors and make educated guesses for each factor. Some factors will be too large and others too small, but the answer should be reasonably close to an acceptable number. I did not show this in the video but the area required for 7.4 billion people is a square about 20 miles on each side. |

Fermi Problem | Example (8 minutes) This Fermi Problem asks for the number of oil changes to cars in the USA on a Tuesday. Often, the correct answer to a Fermi Problem is not known. A general principle is that you should break the problem into many factors and make educated guesses for each factor. Some factors will be too large and others too small, but the answer should be reasonably close to an acceptable number. I estimate that there are about a million oil changes each day. |

Total Number of Vehicles on the USA Interstate Highway System | Example (8 minutes)This video will produce an estimate of the total number of cars and trucks that are on the Interstate Highway System in the USA at one time. This is an example of a Fermi Question. The answer is unknown. By using several guesses of factors used in the calculation it is hoped that a reasonable estimate is produced. |

Weight of Garbage Thrown Out in One Year by a Family of Four-USA | Example (5 minutes)This video will estimate the total weight of garbage thrown in one year out by a family of four in the USA. This is an example of a Fermi Problem. The answer is unknown but you can produce a reasonable estimate of the answer by guessing at several factors as you produce the estimate. |

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Motion | |

Distance Displacement Scalar Vector | Lecture (11 minutes) This video starts the discussion of Chapter 2 of OpenStax College Physics. The terms distance, displacement, scalar, and vector are briefly discussed. |

Speed, Velocity, Kinematics | Lecture (8 minutes) This video discusses speed and velocity. The material is based on chapter 2 of OpenStax College Physics. |

Acceleration, Kinematics | Lecture (9 minutes) This video discusses the definition and meaning of acceleration. This material relates to Chapter 2 of OpenStax College Physics. |

Kinematic Equations Constant Acceleration One Dimension | Lecture (7 minutes) This video derives the four kinematic equations for constant acceleration in one dimension. This material relates to Chapter 2 of OpenStax College Physics. |

Concepts Related to Kinematic Equations | Concepts (9 minutes) This video discusses concepts related to Kinematic Equations. Topics discussed are: displacement vs. distance; distance = rate times time; constant acceleration required; selection of value for starting position; acceleration due to gravity for object at top of its vertical motion. |

Motion Graphs ... Position, Velocity, Acceleration | Example (5 minutes) This video presents two graphs of position vs. time. The value of the slope of the line on the position graph is used to produce the velocity graph. The slope of the line on the velocity graph is used to produce the acceleration graph. This material relates to Chapter 2 of OpenStax College Physics. |

Kinematic Equations Constant Acceleration Examples | Lecture and Examples (13 minutes) This video discusses the four kinematic equations that apply when the acceleration is constant. Some concepts and some specific examples are discussed. This material relates to Chapter 2 of OpenStax College Physics. |

One Dimension Kinematics, Race Car Acceleration | Example (5 minutes) A race car starts from rest and achieves a velocity of 250 miles per hour after traveling one-eighth of a mile. Assume the acceleration is constant. Determine the acceleration value. |

Kinematics, Car Catches Up With Truck | Example (15 minutes) This example uses the kinematic equations to calculate how much time is required for one vehicle to catch up with another vehicle for the situation where the second vehicle had a higher initial speed but only the first vehicle accelerates. The first vehicle accelerates after a few seconds. |

Two Cars Traveling in same Direction-One Has Higher Speed | Example (5 minutes)Two cars are traveling in the same lane on a highway. The car in front is traveling slower than the car that is behind. This video calculates the time for the trailing car to catch the front car for two different speeds of the leading car. |

Two Cars Side By Side-One Has Constant Speed-One Accelerates | Example (13 minutes)In this video two cars are side-by-side at time = 0 seconds. One car is moving at a constant speed. The other car starts from rest and accelerates. The video shows how to calculate the time until the cars are side-by-side again. |

Kinematics, Ball Leaves Helicopter | Example (14 minutes) In this kinematics problem a ball and helicopter are moving upward. At a certain height above the ground the ball rolls out of the helicopter. The maximum height of the ball and the time to hit the ground are calculated. |

Kinematics, Two Objects Approaching | Example (11 minutes) In this kinematics example two objects are approaching each other with different speeds. One object experiences friction and is slowing down. The time of the collision is calculated and the distance each object moves is calculated. |

Kinematics, Airplane Takeoff Acceleration and Runway Length | Example (5 minutes) On a day when the wind speed is zero a plane starts from rest and lifts off after 38 seconds of constant acceleration. The airspeed required for lift off is 150 mph. The acceleration and minimum required length for the runway are calculated. |

Kinematics, Minimum Length of Runway for Plane Taking Off Into Wind and With Wind | Example (6 minutes) An airplane starts form rest on a straight runway. There is a 30 mph wind parallel to the runway. The plane accelerates uniformly at 1.6 m/s2. The airspeed at lift off is 160 mph. The required length for the runway is calculated for the case that the plane takes off into the wind and for the case that the plane takes off while moving in the same direction as the wind. |

Car Constant Acceleration for Given Distance and Time | Example (8 minutes) A car starts from rest and has constant acceleration. The elapsed time and distance traveled in a straight line are give. The final speed and acceleration are determined. A brief discussion is given on average velocity and distance traveled for half of the elapsed time. |

Vertical Motion Free Fall | Lecture (8 minutes) This video discusses the concepts for vertical motion for which air resistance can be ignored. One example is worked in the video. This material relates to Chapter 2 of OpenStax College Physics. |

Vertical Motion of a Ball | (Example 7 minutes) A ball is launched verticallly from ground level. The maximum height, time to move upward, time to fall back to the ground, and speed just before impact are determined. |

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Projectile Motion | |

Projectile Motion | Lecture (14 minutes) This video briefly describes the concepts and solution methods for projectile motion problems. This material relates to Chapter 3 of OpenStax College Physics. |

Concepts for Motion in Two Dimensions, Vectors | Concepts (5 minutes) This video discusses concepts for vectors and projectile motion (i.e. motion in two dimensions). |

Projectile Motion Example | Example (6 minutes) This video shows how to calculate horizontal and vertical components for an object that is launched with a given speed and direction. The video provides a step by step solution to finding the range for the object. The time to the maximum height of the motion is used to find the time in the air. This material relates to chapter 3 of OpenStax College Physics. |

Projectile Motion Baseball 1 | (Example 14 minutes) In this problem a baseball is struck by a bat at a given distance above home plate. The ball leaves the bat at a given angle. The ball crosses the outfield fence at a given height and the distance to the fence is given. The time for the ball to travel to the fence and the initial velocity of the ball are determined. Air resistance is ignored. |

Projectile Motion Baseball 2 Speed, Angle Unknown | (Example 11 minutes) In this problem a baseball is struck by a bat at a given distance above home plate. The ball crosses the outfield fence at a given height and the distance to the fence is given. The time for the ball to travel to the fence is given. The initial velocity (magnitude and angle) of the ball are determined. Air resistance is ignored. |

Projectile Motion Calculate Launch Angle Max Height Time | (Example 15 minutes) A ball is launched at a given speed at an unknown angle. The range of motion is given. The ball lands at the same height it was launched. |

Projectile Motion Dart and Apple 1 aka Hunter and Monkey | (Example 9 minutes)A dart gun is aimed at an apple hanging in a tree. The dart is launched at 16 m/s at an angle of 30 degrees. The dart gun is 1.3 meters above the ground. The apple is 5.6 meters above the ground. Does the dart hit the apple? |

Projectile Motion General Dart and Apple 2 aka Hunter and Monkey | (Example 11 minutes) A dart gun is aimed at an apple in a tree. When the dart is fired the apple starts falling to the ground. This video gives a general proof that the dart will hit the apple regardless of the speed of the dart. |

Projectile Motion Dart and Apple 3 Hit Ground Together aka Hunter and Monkey | (Example 11 minutes) A dart gun is aimed at an apple hanging in a tree. The dart is launched at an angle of 30 degrees. The dart gun is 1.3 meters above the ground. The apple is 5.6 meters above the ground. Determine the launch speed for the dart such that the dart hits the apple at the instant the apple hits the ground. |

Projectile Motion, Ball Launched from Cliff; Distance, Time In Air, Given | Example (11 minutes) In This projectile motion a ball is thrown from a cliff with a known height. The horizontal distance traveled and the time in the air are given. The launch angle and speed are determined. |

Projectile Motion, Basketball Shot | Example (8 minutes) This video shows how to calculate the initial speed of a basketball that is launched at a given angle, from a given height above the floor, and given the height of the basketball goal. Air resistance is ignored. The horizontal and vertical equations are used to solve for the launch speed. The maximum height of the basketball is also calculated. |

Projectile Motion Example, Height, Time in the Air, Range | Example (7 minutes) In this projectile motion example the launch velocity is given. The maximum height, the time in the air, and the range are calculated. Air resistance is ignored. The ball is launched over level ground. |

Projectile Motion, Two Balls Collide in the Air, Max Height, Time | Example (9 minutes) In this projectile motion example one ball is launched with a given speed and angle. The second ball is launched straight upward at a given speed. The video shows how to calculate the time delay between the launch of ball 1 and ball 2 such that the balls hit at the maximum height of ball 1. This is not a momentum problem, it is a kinematics problem. Air resistance is ignored. |

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Vectors | |

Vector Addition Using the Graphical Method | Lecture (16 minutes) This video starts the discussion of Two Dimensional Motion. The video shows how to add vectors using the graphical, head-to-tail, method. This material relates to Chapter 3 of OpenStax College Physics. |

Trig Functions Review and Analytic Addition of Vectors | Lecture (18 minutes) This video has a quick review of right triangles and trig functions. Then the video discusses how to add vectors analytically. The analytic addition of vectors produces more accurate results than the graphical addition of vectors. This material relates to Chapter 3 of OpenStax College Physics. |

Vector Addition Real World Problems | Example (7 minutes) This video discusses rowing a boat across a river, and flying a plane when there is a wind. Vector addition is used to solve each problem. This material relates to Chapter 3 of OpenStax College Physics. |

Vector Addition, Drone, Three Vectors | Example (17 minutes) This video shows how to calculate the distance traveled and displacement for a drone that has 3 segments of motion. The length and angle referenced to NSEW are given. The components of the vectors are calculated and added. The resultant vector is determined |

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Newton's Laws | |

Introduction to Force and Newton's Laws | Lecture (10 minutes) This video introduces the concept of force and Newton's Laws. Newton's three laws of motion are listed. Free body diagrams are described. This material relates to Chapter 4 of OpenStax College Physics. |

Netwon's Law F = ma | Lecture (15 minutes) This video reviews terminology involved in F=ma. The video shows examples of applying F=ma. Acceleration is calculated based on given force and mass values. This material relates to Chapter 4 of OpenStax College Physics. |

Newton's Third Law and F=ma Examples | Lecture and Examples (17 minutes) This video reviews Newton's Three Laws and then expands the discussion of Newton's Third Law. The video also has two examples of problem solving with F=ma. One problem involves an elevator. The second problem has two masses connected by a string on a horizontal, frictionless, surface. This material relates to Chapter 4 of OpenStax College Physics. |

Forces Problem Solving and Four Fundamental Forces | Example and Lecture (7 minutes) This video gives some general guidance on solving problems using F=ma. The video briefly discusses the four fundamental forces: electrical, gravity, strong nuclear, and weak nuclear. This material relates to Chapter 4 of OpenStax College Physics. |

F=ma Elevator Problem | Example (4 minutes) This video shows how to solve for the contact force acting on a person's feet in an elevator. The force is calculated for velocity=0, constant velocity and two values of acceleration of the person in the elevator. This material relates to Chapter 4 of OpenStax College Physics. |

F=ma Atwood Machine Acceleration and Tension | Example (7 minutes) This video calculates the acceleration and tension in a connecting string for an Atwood's Machine problem. This material relates to Chapter 4 of OpenStax College Physics. |

Newton's Second Law F ma Three Objects, Tension | (Example 11 minutes) A 12 kg object hangs freely from a string that is connected to a 9 kg object that rests on a horizontal table. A string connects the 9 kg object to a 5 kg object on the table. The coefficient of static friction is 0.26 and the coefficient of kiinetic friction is 0.17. The system starts at rest. Determine 1) if the system moves, 2) the acceleration, 3) the tension in the strings. |

F=ma Inclined Plane No Friction | Example (7 minutes) This video calculates the acceleration of an object that is released form rest on a frictionless inclined plane. The time required for the object to reach the bottom of the ramp is determined. This material relates to Chapter 4 of OpenStax College Physics. |

Motion on Inclined Plane, Acceleration, Time, No Friction | Example (6 minutes) This video shows how to calculate the acceleration of an object on an inclined plane. The time required to move a given distance is also determined. Friction is ignored. The Free Body diagram is shown. |

Force Equilibrium, Ramp, Tension in Rope, No Friction | Example (6 minutes) A box is at rest on a ramp. A rope pulls on the box in an upward direction not parallel to the ramp. The tension in the rope is determined. Friction is ignored |

Bouncing Ball Average Force | Example (7 minutes) A ball is dropped 4 meters onto a floor. After the partially elastic collision the ball reaches a height of 2.5 meters. The duration of the collision is 0.08 seconds. The average force of the collision is determined using two methods. |

Apollo Saturn V Launch Acceleration, Kinematics | Example (7 minutes) This video calculates the acceleration of the Apollo Saturn V rocket at the time of launch. The velocity and distance traveled after 10 seconds are approximately determined. I assume constant acceleration just for a quick calculation. This ignores the change in mass of the system as it moves upward. |

Apollo Lunar Lander Acceleration, Throttle Control | Example (11 minutes) This video calculates the acceleration of the Lunar Lander at the start of the de-orbit burn and near the lunar surface both for landing and take-off. The mass of the LEM near the surface of the Moon is estimated. The throttle setting % that would make the LEM hover is approximately calculated. |

Model Rocket-Speed-Height-Physics Example Problem | Example (17 minutes)This physics educational video shows how to calculate the speed and height of a model rocket given the rocket mass, thrust of the rocket, and time the thrust is active. The mass of the rocket is assumed to be constant so the calculated acceleration will be constant and Calculus tools are not required. The launch occurs at the surface of the Earth. Air resistance is important in an actual launch but it is ignored for this calculation. |

Object Falls and is Pushed Horizontally-Find Velocity at Impact on the Ground | Example (13 minutes)In this educational physics video a block of wood is released from rest. It falls towards Earth and at the same time is pushed horizontally by a model rocket engine. The velocity (speed and direction) at impact with the ground is calculated. Problem- solving principles for physics problems are emphasized. |

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Friction | |

Friction and Force from Springs | Lecture (8 minutes) This video gives a brief introduction to the concept of friction. Static and Kinetic friction is discussed. The equations used to calculate the force of friction are presented. There is a brief comment on the force due to springs. This material relates to Chapter 5 of OpenStax College Physics. |

F=ma for System of 4 Objects, Friction, Acceleration, Tension | Example (17 minutes) This video analyses the motion of a system which has three objects on a table and one object hanging freely. Massless strings connect the objects. Friction is present for the objects on the table. The video shows how to determine if the system will start moving, calculates the acceleration, and calculates the tension in each string. The concept of an external force is emphasized. |

F=ma Object on Inclined Plane with Friction | Example (14 minutes) This video calculates the acceleration for a system that includes a mass on an inclined plane, friction, and a second object hanging at the end of a rope that connects the objects. The video discusses the analysis of forces, static and kinetic friction, internal and external forces. |

F ma Two Objects Connected by String with a Plane and Friction | Example (9 minutes) Two objects are connected by a massless string. One object rests on a plane. The other object hangs freely from the string. Friction is present. Does the system move? What is the acceleraton? What is the value of the tension in the string? |

Force Equilibrium, Ramp, Box, Rope, Friction | Example (10 minutes) A box is at rest on a ramp. Friction is present. The video shows how to determine if the box slides down the ramp. Then we consider the effect of a rope pulling on the box up the ramp. The tension in the rope is determined such that the box is in equilibrium. The rope's effect on the normal force is taken into account. |

Object Pushed on Horizontal Surface, Then Slides Up Ramp With Friction | Example (10 minutes) An object is pushed by a constant force for a given distance on a horizontal, frictionless surface. The velocity is determined. Then the object slides up an inclined plane that does have friction. The distance the object moves up the incline before coming to rest is determined. |

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Circular Motion | |

Circular Motion and Introduction to Centripetal Acceleration | Lecture (13 minutes) This video introduces the basic formulas of circular motion: S = r * angle and V = r * angular velocity. The video discusses the radian and the conversion of degrees to radians. The direction of centripetal acceleration is discussed. This material relates to Chapter 6 of OpenStax College Physics. |

Centripetal Force and Centrifugal "Force" Introduction | Lecture (12 minutes) This video discusses the direction of centripetal force and its relation to the mass, velocity, and radius of the circle. The motion of cars traveling around corners and the centrifuge are discussed.Prof. The concept of Centrifugal and observations in non-inertial reference frames is briefly discussed. The Coriolis effect is discussed. This material relates to Chapter 6 of OpenStax College Physics. |

Centripetal Force, Speed of Object Moving in a Circle, String Provides Fc | Example (5 minutes) This video calculates the speed of an object moving in uniform circular motion. The object is moving in a horizontal circle. A string connects the object to a weight which provides the centripetal force. |

Centripetal Acceleration and Force Hard Drive and Car Around Corner | Examples (7 minutes) This video calculates the centripetal acceleration for a computer hard drive. The video also calculates the maximum speed a car could have to safely drive around a corner given conditions for friction and radius of the corner. This video relates to Chapter 6 of OpenStax College Physics. |

Centripetal Force, Safe Speed for Car Driving Around a Curve | Example (7 minutes) This video calculates the maximum safe speed for a car that is driving around a curve on a flat highway (no banking). Static friction provides the centripetal force. The mass of the car does not affect the calculation of the safe speed. |

Centripetal Force, Find Angle for Banked Curve, No Friction | (Example 9 minutes) A banked curve is being desgined to allow cars to travel safely around the curve at 50 mph. The radius of the circle is 230 meters. Determine the angle of the banking. Assume 0 friction. |

Uniform Circular Motion Ferris Wheel Normal Force | (Example 7 minutes) A person is riding on a Ferris Wheel in uniform circular motion. The mass of the person, the diameter of the Ferris Wheel, and the time for one revolution are given. The value of the normal force at the top and bottom of the ride are determined. |

Centripetal Force Ferris Wheel | Example (6 minutes) This video uses the concept of centripetal force to calculate the force the seat of the Ferris wheel applies to the person on the seat. This video relates to Chapter 6 of OpenStax College Physics. |

Centripetal Acceleration Truck Tire Tread | Example (9 minutes) The tread of truck tires can separate from the underlying layers and leave debris on the side of highways. This video calculates the centripetal acceleration and force for the case of a truck moving at 65 mph. |

Centripetal Force, Angular Momentum, Earth's Orbit With Reduced Mass for Sun | Example (9 minutes) This video calculates the change in the velocity of the Earth and the radius for the Earth's orbit if the Sun's mass is reduced by 50%. It is assumed the orbit is circular. The force of gravity provides the centripetal force. The angular momentum of the Earth is constant. This assumes (INCORRECTLY) that the orbit of the Earth is cicular before and after the Sun's mass is reduced. |

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Gravity | |

Newtons Law of Gravity, Orbits, Space Race | Lecture (22 minutes) This video discusses Newton's Law of Gravity F = GmM/R/R. The video shows the results of using gravity as the centripetal force. Some history of the Space Race of the 1950's is discussed. This material relates to Chapter 6 of OpenStax College Physics. |

Period and Velocity for a Satellite in Low Earth Orbit | Example (6 minutes) This video shows how to calculate the period and velocity for a satellite in a low orbit around the Earth. The gravitational force supplies the centripetal force. The equations are derived and then used for the calculations. This material relates to Chapter 6 of OpenStax College Physics. |

Altitude for a Geosynchronous Satellite | Example (4 minutes) This video shows the calculation of the altitude of a geosynchronous satellite. This satellite has an orbit period of 24 hours, which matches the time for one rotation of the Earth. Gravity supplies the centripetal force. The equation for the radius of the orbit (cubed) is derived and then the calculation is performed. The altitude is found by subtracting the Earth's radius from the radius of the orbit. This material relates to Chapter 6 of OpenStax College physics. |

Calculate Mass of Asteroid that is Observed to have a Moon | Example (5 minutes) This video calculates the mass of a hypothetical asteroid given data on the orbit of a small moon around the asteroid. The equation is derived by setting the gravitational force expression equal to the expression for centripetal force. The mass of the asteroid is calculated using the orbital data. This material relates to Chapter 6 of OpenStax College Physics. |

Calculate Mass of Sun Using Data on Earth's Orbit | Example (5 minutes) This video shows how to calculate the mass of the Sun if the radius of the Earth's orbit and the time for one orbit is known. The force of gravity provides the centripetal force. For the purpose of this approximate calculation it is assumed that the Earth's orbit is a circle. |

Period of Orbit in Terms of Density of Planet | Example (8 minutes) This video shows how to derive the period of a close orbit in terms of the density of a planet. The idea for this video came from a posting by Gary White to a Physics Listserv many years ago. |

Gravitational Attraction Two Spheres Unreasonable Result | Example (6 minutes) The problem uses Newton's Law of Gravitation to solve for the distance between the centers of two spheres. The masses of the spheres and the value of the gravitational force are given. The radii and density of the spheres are determined. The density is compared to lead. The specified force is too large. |

Gravitational Force For Two Lead Spheres | Example (5 minutes) Two lead spheres are touching. The radius of each sphere is given. The mass of each sphere is determined by using density multiplied by volume. The distance between the centers of the spheres is determined and then the gravitational force between the objects is determined. |

Earth Satellite With Period of 12 Hours Find Orbit Distance | Example (7 minutes) This video shows how to determine the altitude of a satellite that orbits the Earth once every 12 hours. The centripetal force is provided by the force of gravity. The radius of the circular orbit is determined and then the altitude is determined. |

Location Where Forces of Gravity From Earth and Moon Balance | Example (10 minutes) This video calculates the location between the Earth and the Moon where the force of gravity on the Apollo spacecraft from the Earth and the force of gravity from the Moon would add to zero. As expected, the location is much closer to the Moon than to the Earth. |

Period of Apollo Spacecraft Around the Moon | Example (7 minutes) This video calculates the period (time for one orbit) for the Apollo 11 command module in orbit around the Moon. For the calculation the orbit was approximated by a circle. The gravitational force of the Moon on the spacecraft provided the centripetal force. |

Does Our Moon Orbit The Sun or Earth | Example (7 minutes) For an observer on the Earth it appears that the Moon orbits the Earth. In this video the force of gravity between the Sun and Moon is calculated. Also, the force of gravity between the Earth and Moon is calculated. The results are discussed. This video is a basic calculation. You may wish to read the article on "Hill Sphere" in Wikipedia. |

Location Where Forces of Gravity From Sun and Earth Balance | Example (11 minutes) This video does a simple calculation to determine where the forces of gravity from the Sun and from the Earth on a spacecraft have the same size but opposite direction. This is not a dynamical calculation with orbital motion. The objects are stationary. The balance location is between the Sun and the Earth at a distance of about 40 times the radius of the Earth from the Earth's center. This does not mean that the spacecraft would leave an orbit around the Earth if it were put into orbit around the earth at this location. For a discussion of how near the Earth an object must be to keep in orbit around the Earth please read the Wikipedia article on "Hill Sphere." |

Time For Object To Fall To The Sun From 1AU and Speed | Example (10 minutes) This video calculates the approximate time for an object to fall into the Sun when it starts from rest at a distance of 1 A.U. (position of Earth's orbit). The video discusses why some formulas cannot be used to do this calculation. The video uses Kepler's Third Law to find the time. The video also calculates the speed of the object when it reaches the photosphere of the Sun. |

Saturn's Rings Periods of Inner and Outer Particles | Example (9 minutes) This video shows how to calculate the orbital period for particles at the inner and outer edges of the substantial rings of Saturn (D and F rings). The orbital distance is found by adding the altitude to the radius of Saturn. The gravitational force provides the centripetal force for the particles. The orbit periods are compared to the rotation time for Saturn. |

Mass of Pluto From Charon Orbit Data | Example (9 minutes) This video shows how to calculate the mass of Pluto from the orbit data for Charon. A modified form of Kepler's Third Law is used. The mass of Pluto is compared to the mass of our Moon. The density of Pluto is calculated and discussed. |

Phobos and Deimos-Orbit Times for Moons of Mars-Rise at Which Horizon | Example (12 minutes)This video calculates the orbit period for the moons of Mars, Phobos and Deimos. The Centripetal Acceleration is provided by the Force of Gravity. There is a short discussion of where an observer on Mars would see the moons rise-on the East or West Horizon |

Geo-Synchronous Orbit Sizes for some planets and our Moon | Example (8 minutes) This video calculates the sizes of "geo"-synchronous orbits for Earth, Venus, Mars, Jupiter, and our Moon. The method used is to balance the centripetal force with the force of gravity. Gravitational forces of the Sun and other planets are ignored. A few comments are made as to whether the orbit is feasible for Venus and our Moon. |

Gravity Balance Position Sun and Planets, Earth Moon | Example (13 minutes) This video calculates the location where the forces of gravity balance for the Sun and the planets Earth, Mars, Jupiter, and for the case of the Earth and the Moon. The Hill Sphere is briefly discussed. It is noted that our Moon experiences more force from the Sun than from the Earth. Our Moon orbits the Sun, not the Earth, but the Earth has enough influence on the Moon to keep the Moon near the Earth. |

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Conservation of Energy | ||

Work, Kinetic Energy, Potential Energy | Lecture (24 minutes) This video introduces the concepts of work, kinetic energy, and potential energy. The requirement that the force vector (or a component) and the displacement vector are parallel is emphasized. The connection between work and change in kinetic energy is discussed. Gravitational potential energy and potential energy from springs is discussed. The negative work of friction is discussed. Conservative and nonconservative forces are mentioned. This video relates to Chapter 7 of OpenStax College Physics. | |

Conservation of Energy, Efficiency | Lecture (9 minutes) This video discusses conservation of energy for the case when work is done by a non-conservative force (friction). The video gives a summary of the general problem and shows two specific examples. This material relates to Chapter 7 of OpenStax College Physics. | |

Average Power, World Energy Production, CO2 in Earth's Atmosphere | Lecture (10 minutes) This video shows how to calculate the average power (work//time). The video briefly discusses world energy production. The video briefly discusses the greenhouse effect and the correlation between carbon dioxide in our atmosphere and global temperature. This material is related to Chapter 7 of OpenStax College Physics. | |

Greenhouse Effect, Energy Balance for the Earth | Lecture (16 minutes) This was presented in an Introductory Astronomy class. This video discusses the greenhouse effect due to gases in the Earth's atmosphere. The important molecules are mentioned. Graphs of Temperature and Carbon Dioxide concentration are shown. Sources of carbon dioxide are discussed. | |

Conserve Energy Example, Box Slides Down Frictionless Plane | Example (5 minutes) This video calculates the velocity of a box the instant before it reaches to bottom of a frictionless plane. Two solution methods are used. The first method uses F=ma and a kinematic equation. The second method uses conservation of energy. This video relates to Chapter 7 of OpenStax College Physics. | |

Conservation of Energy Example, Box Slides Down Plane with Friction | Example (6 minutes) This video calculates the velocity of an object just before it reaches the bottom of an inclined plane. Friction is present. The video shows two methods for the calculation. Method 1 uses F=ma and a kinematic equation. Method 2 uses Conservation of Energy. This material relates to Chapter 7 of OpenStax College Physics. | |

Conservation of Energy example, Spring, Box, Friction, Ramp | Example (7 minutes) This video uses the principle of Conservation of Energy to calculate the velocity of a box pushed by a spring and the maximum height the box will reach going up a curved ramp. Friction is taken into account during the initial motion on a horizontal surface. This video relates to Chapter 7 of OpenStax College Physics. | |

Conservation of Energy, Object Slides on Ramp, Compresses Spring | Example (13 minutes) This example problem uses Conservation of Energy to solve the problem. An object slides down a frictionless ramp, then slides on a horizontal surface with friction, then compresses a spring until its velocity is again zero. F=ma and kinematic equations are not useful because the force is variable. The video shows how to set up the conservation of energy equation and how to solve the quadratic equation. The video discusses how to select the correct solution from the two solutions to the quadratic equation. | |

Conservation of Energy, Object Attached to Spring on Frictionless Ramp | Example (10 minutes) This video discusses the motion of an object that compresses a spring as it moves down a frictionless ramp. The gravitational potential energy is ocnverted to potential energy of the spring. The video discusses why the kinematic equations cannot be used. The expression for X is checked for proper units and for reasonably results for two cases of the angle of the ramp. | |

Spring Pushes a Mass, Collision with Another Mass, Projectile Motion | Example (9 minutes) A compressed spring pushes a mass across a horizontal, frictionless, surface. The mass makes an inelastic collision with another mass. 50% of the Kinetic Energy is lost in the collision. The two masses have projectile motion as they move past the edge of the table. The range of motion is determined. | |

Spring Pushes a Mass, Collision With Another Mass, Movement Up Ramp | Example (7 minutes) A spring is compressed. When released, the spring pushes a mass along a horizontal, frictionless, surface into another mass. The two objects stick together, kinetic energy is lost. The two masses slide up a frictionless ramp. The position along the ramp is determined. | |

Conservation of Energy, Frictionless Vertical Track With Loop | Example (8 minutes) An object is a height h above the ground on a vertical frictionless track that has a loop. As the object moves to the top of the loop it briefly has no contact force with the track. The value of h is determined in terms of the radius of the loop. The speed at the top of the loop and at ground level are calculated. | |

Roller Coaster With Friction Conservation of Energy | Example (6 minutes) This video determines the height of the second hill of a roller coaster. The height of the first hill, speed at the top of the first hill, percent of energy lost to friction, and desired speed at the top of the second hill are given. Conservation of Energy and work done by friction are used to find the solution. | |

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Conservation of Momentum, Collisions | ||

Momentum, Impulse, Conservation of mV | Lecture (9 minutes) This video introduces the physics quantity called momentum. The video briefly discusses Newton's 2nd Law that uses change in momentum. The video shows what conditions are required for momentum to be conserved (constant). The video discusses impulse. This material relates to Chapter 8 of OpenStax College Physics. | |

Conserve Momentum, Collisions, Elastic | Lecture (5 minutes) This video briefly shows the derivation of the Law of Conservation of Momentum. The video gives the characteristics of elastic and inelastic collisions. The useful equations for elastic collisions are shown and analyzed of two equal masses. This material relates to Chapter 8 of OpenStax College Physics. | |

Conserve Momentum, Inelastic, Two Dimensions, Rockets | Lecture (9 minutes) This video discusses inelastic collisions and conservation of momentum. The video also discusses two-dimensional collisions and rockets. This material relates to Chapter 8 of OpenStax College Physics. | |

Elastic Collision Small and Large ball fall inline and rebound | Example (4 minutes) This video describes the situation where a low mass ball and large mass ball fall towards a table. In this hypothetical situation both balls are perfectly elastic and they are dropped in a vertical line. The bottom ball hits the table first and rebounds. The smaller ball rebounds off of the bottom ball at a speed of 3V, where V is the velocity the objects had near the table. This material relates to Chapter 8 of OpenStax College Physics. | |

Inelastic Collision, Spacecraft Separates Into Two Pieces | Example (4 minutes) This video calculates the final velocity in a situation where springs push two parts of a spacecraft away from each other. Momentum is conserved but Kinetic Energy is not conserved. This material relates to Chapter 8 of OpenStax College Physics. | |

Impulse and Force for Tennis Racket on Tennis Ball | Example (3 minutes) This video calculates the impulse applied to a tennis ball and the average force of the tennis racket on the tennis ball. This material relates to Chapter 8 of OpenStax College Physics. | |

Falling a Distance Such That You Don't Break A Leg | Example (6 minutes) This video uses the concept of impulse to estimate how the maximum height you could fall and not break a leg. Do not try this at home! (or school!). The video derives an algebraic expression for the maximum height based on the mass of the person, the distance they can crouch at impact, and the force the leg can withstand. This material relates to Chapter 8 of OpenStax College Physics. | |

Conservation of Momentum, How to Get to Shore if On an Icy Lake | Example (6 minutes) This video calculates the velocity for a sled and person after the person throws a concrete block away from her. The sled and person were somehow in the middle of a frictionless, icy lake. This material relates to Chapter 8 of OpenStax College Physics. | |

Two People Push Each Other on Ice Find Force | Example (5 minutes) Two people are standing near each other on ice. The masses of the people are given. They push each other with a constant force for 1.2 seconds. One person is moving at 0.8 m/s after the push. Find the force of the push and the velocity of the other person. | |

Person Moving on Ice Throws Rock | Example (5 minutes) A 50 kg person holds a 4 kg rock while moving to the right on frictionless ice at 1.23 m/s. The person throws the rock behind them at a speed of 3 m/s at an angle of 36 degrees above the horizontal. The velocity of the person after the throw is determined. | |

Elastic Collision, Calculate the two final velocities | Example (4 minutes) This video shows how to calculate the final velocities for an elastic collision. The video makes use of an equation that results when conservation of momentum and conservation of kinetic energy are combined. This material relates to Chapter 8 of OpenStax College Physics. | |

Conserve Momentum, Inelastic Collision, Football tackling | Example (3 minutes) This video calculates the final velocity after a tackle is made in football. The collision is inelastic. Momentum is conserved. This material relates to Chapter 8 of OpenStax College Physics. | |

Ballistic Pendulum, Conserve Momentum and Energy | Example (4 minutes) This video shows the calculations involved in a ballistic pendulum problem. A bullet is caught by a block of wood. The system swings to some maximum height after the inelastic collision. Conservation of momentum is used to find the velocity of the wood+bullet after the collision. Conservation of energy is used to calculate the maximum height for the swing. This material relates to Chapter 8 of OpenStax College Physics. | |

Bouncing Ball Average Force | Example (7 minutes) A ball is dropped 4 meters onto a floor. After the partially elastic collision the ball reaches a height of 2.5 meters. The duration of the collision is 0.08 seconds. The average force of the collision is determined using two methods. | |

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Statics, Torque | ||

Static Equilibrium, Torque, Stability | Lecture (9 minutes) This video discusses the concepts for equilibrium. The net external force must be zero and the net external torque must be zero. The video illustrates how torque is calculated and briefly discusses equilibrium. This material relates to Chapter 9 of OpenStax College Physics. | |

Static Equilibrium Problems, Concepts | Lecture (5 minutes) This video describes the problem solving approach commonly used for static equilibrium problems. General problem situations are discussed. No examples are worked step by step in this video. This material relates to Chapter 9 of OpenStax College Physics. | |

Static Equilibrium Problem, Beam attached to wall, supported by cable | Example (6 minutes) This video shows how to calculate the unknown forces in a static equilibrium problem. Three equations are used. The forces in the Y direction sum to zero. The sum of the forces in the X direction is set to zero. The axis of rotation is set to be at the hinge so the torque equation only has one unknown. This material relates to chapter 9 of OpenStax College Physics. | |

Static Equilibrium, Horizontal Beam, Person Standing on Beam | Example (7 minutes) A horizontal beam has two supports. A person stands on the beam between the two supports. The values of the two upward forces of the supports on the beam are determined. | |

Static Equilibrium, Beam, Two Supports, Person on beam walks towards one end | Example (8 minutes) A horizontal beam is supported at two locations. A person starts on the beam between the supports. The person walks towards one end of the beam. The location of the person on the beam when the beam starts to tip is determined. | |

Ladder Leaning Against Wall With Friction | Example (13 minutes) A ladder is leaning against a wall. The coefficient of friction is not zero at the ground and not zero at the wall. The torque equation starts with four unknowns. Substitutions are made such that the angle is the only unknown. The angle of the ladder with respect to the ground is determined such that the ladder is stable. At a smaller angle the ladder would slip. Specific values for the coefficients of friction are given and the angle is computed. | |

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Rotation Kinematics and Dynamics | |

Rotational Kinetic Energy, Conservation of Angular Momentum, Precession | Lecture (13 minutes) This video discusses how force times distance for rotational motion creates rotational kinetic energy. The video discusses conservation of angular momentum. The video discusses the precession of a bicycle wheel and the Earth. This material relates to Chapter 10 of OpenStax College Physics. |

Rotational Kinematics and Dynamics | Lecture (9 minutes) This video discusses the description of rotation motion and the connection between angle, rotational velocity and rotational acceleration. The video makes the connections between linear and angular variables. The video discusses what causes angular acceleration (torque) and what resists angular acceleration (rotational inertia). This material relates to Chapter 10 of OpenStax College Physics. |

Example: Rotational Inertia, Torque, Angular Acceleration, Velocity | Example (6 minutes) This video shows how to solve a problem that asks for the calculation of rotational inertia, torque, angular acceleration, and linear velocity. The problem deals with a person sitting on a merry-go-round. This material relates to Chapter 10 of OpenStax College Physics. |

Rotational Inertia, Angular Acceleration | Example (7 minutes) An object consists of a large cylinder and a smaller cylinder attached coaxially to one end of the larger cylinder. The masses and dimensions of the cylinders are given. The total rotational inertial (moment of inertia) is calculated. Two masses are attached to strings which are wound in opposite directions around the two cylinders. The net torque and the angular acceleration are determined. |

Example: Rotational Kinetic Energy, Conserve Angular Momentum | Example (6 minutes) This video shows how to calculate rotational kinetic energy. The video also shows how to calculate the final angular velocity for the case when the rotational inertia value changes. The setting of the problem is a person holding masses in her hand while rotating on a frictionless platform. This material relates to Chapter 10 of OpenStax College Physics. |

Example Angular Momentum for Earth in Orbit and Earth Spinning | Example (7 minutes) This video shows how to calculate the angular momentum for the Earth in its orbit and for Earth as it rotates on its axis. This material relates to Chapter 10 of OpenStax College Physics. |

Earth's Velocity and Orbit if Sun Half Mass | Example (9 minutes) This video calculates the change in the velocity of the Earth and the radius for the Earth's orbit if the Sun's mass is reduced by 50%. It is assumed the orbit is circular. The force of gravity provides the centripetal force. The angular momentum of the Earth is constant. |

Rotational Dynamics, Wheel, String, Descending Mass, Find Acceleration | Example (16 minutes) A small bicycle wheel has its rubber tire removed. The frictionless axle is mounted horizontally. The tire spins in a vertical plane. String is tied to the rim of the wheel and wrapped around the wheel. The free end of the string partially supports a descending mass. The acceleration, tension in the string, and speed after the mass descends 1.7 meters are calculated. |

Rotational Dynamics, Bullet Collides with Rod, System Rotates | Example (9 minutes) A bullet is fired horizontally at a horizontal rod. The rod is mounted on a frictionless vertical axle. The angular velocity of the system is determined after the bullet is captured by the rod. |

Merry Go Round, Two Torques, Angular Speed, Rotational Dynamics | Example (10 minutes) A merry-go-round slows down due to friction in its axle. A person pushes on the edge of the merry-go-round to increase its angular speed. The frictional torque is calculated from data on the change in angular speed and the time interval. The time required for the person to bring the speed back up to the initial value is calculated. This problem uses rotational kinematics and dynamics. |

Horizontal Disk, Torque, Centripetal Force, Friction, Rotational Dynamics | Example (13 minutes) A horizontal disk has a block resting on it at the edge of the disk. A rope wound around the edge of the disk creates a torque to increase the angular velocity of the disk. Friction supplies the centripetal force required to keep the block on the disk. The increased angular speed eventually reaches a value for which the friction force cannot supply the required centripetal force. The time that the torque must be applied to create this condition is calculated. |

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Fluids | |

Fluids, Density, Pascal's Principle | Lecture (16 minutes) This video briefly discusses differences between solids, liquids, gases. The video discusses density and the calculation of m*vol. This material is in Chapter 12 of OpenStax College Physics, Pascal's Principle can be used to build a machine. |

Weight of Air in a Room Using Density Formula | Example (4 minutes) This video presents an example problem that uses the formula density = mass / volume. The dimensions of a room in feet are converted to meters. The mass of the air in the room in kilograms is determined by using the standard density of air. The weight in Newtons is found by multiplying by the acceleration due to gravity. The weight is converted to pounds for the benefit of those who live in the United States. This material relates to Chapter 11 of OpenStax College Physics. |

Pressure on a Floor Due to A Person Standing on the Floor | Example (5 minutes) This video is an example problem regarding pressure. Pressure is calculated using Force / Area. The problem calculates the pressure for a person wearing flat shoes and for a person wearing high heels. This video relates to Chapter 11 of OpenStax College Physics. |

Pascal's Principle in a Hydraulic System | Example (5 minutes) This video is an example problem that uses Pascal's Principle to calculate the available force in a hydraulic system. The extra pressure created by the input force exists throughout the hydraulic fluid. The output force is larger than the input force because the area of the output piston is larger than the area of the piston where the force is applied. The penalty paid in all machines that multiply force and the work-in and work-out are briefly discussed. This material relates to Chapter 11 of OpenStax College Physics. |

Archimedes Principle Buoyant Force Wood and Lead in Water | Example (8 minutes) This video is an example problem that uses the concept of Buoyant Force to calculate the mass of lead that must be attached to a piece of wood to fully submerge, but not sink, the wood. The video makes extensive use of the formula density = mass / volume. The video uses the concept of specific gravity. This material relates to Chapter 11 of OpenStax College Physics. |

Archimedes Principle, People Float on Mat | Example (6 minutes) This video calculates the minimum area needed for a flotation mat to support 4 people (600 pounds) in fresh water. The density and thickness of the mat are given. The Buoyant Force is expressed using Archimedes Principle. The expressions for the metric weights of the people and mat are shown. |

Archimedes Principle, Density of Irregular Object | Example (5 minutes) This video shows how to determine the density of an irregularly shaped rock. The rock is weighed while in air and while submerged in fresh water. The weight and volume of the string on the rock is ignored. Archimedes Principle is used to find the volume of the rock. |

Water Bottle Fountain on Airplane | Example (10 minutes) A rigid water bottle is partially filled at an airport where the air pressure is 1.013 x 10^5 Pa. The bottle has an interior straw and drinking port that can be sealed. A small fountain effect occurs when the passenger opens the drinking port when the cabin pressure is 0.98 x 10^5 Pa. The physics principle that explains the effect is briefly explained. The approximate height of the water fountain is calculated. |

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Temperature, Ideal Gas, Expansion | |

Measurement of Temperature, Thermal Expansion, Expansion of Water | Lecture (14 minutes) This video discusses temperature. Fahrenheit, Celsius, and Kelvin scales are discussed. The physical effects caused by changes in temperature are briefly discussed. The reason ice forms on the tops of lakes is described. The changes in length and volume due to changes in temperature are discussed. This material relates to Chapter 13 of OpenStax College Physics. |

Ideal Gas, Ideal Gas Law, Distribution of Speeds | Lecture (9 minutes) This video discusses the Ideal Gas Law. PV=nRT and PV=NkT are discussed. Units for the variables are discussed. The Maxwell-Boltzmann distribution of speeds is discussed. This material relates to chapter 13 of OpenStax College Physics. |

Ideal Gas Law Determine Pressure as Temperature Changes | Example (5 minutes) A rigid, sealed, container contains an ideal gas at a given pressure and temperature. The temperature is reduced. The new pressure is determined. The video emphasizes that the Celsius temperature must be converted to Kelvin (because the conversion involves addition). The units of atmospheres for the pressure do not need to be converted to Pascals because this conversion only involves multiplication of a factor. |

Kinetic Theory Vrms Phase Diagrams | Lecture (13 minutes) This video discusses why gas creates a pressure on its container. The video describes how to calculate the vrs, root-mean-square, velocity. The video describes the Maxwell-Boltzmann distribution of speeds. The video briefly discusses phase diagrams and the solid, liquid, vapor, gas states of matter for water and carbon dioxide. This material relates to Chapter 13 of OpenStax College Physics. |

Linear Thermal Expansion Calculation | Example (5 minutes) This video shows how to calculate the change in length for an aluminum rod where the initial and final temperatures are given. The video shows how to covert Fahrenheit to Celsius. |

Bimetallic Strip Linear Expansion | Example (8 minutes) This video calculates linear expansion for a bimetallic strip of aluminum and brass. The temperature required to cause the aluminum strip to have 0.3% longer length than the brass strip is determined. The strips are in thermal contact so their initial and final temperatures are equal. The concepts of linear thermal expansion are used. |

Volume Expansion for Gasoline in Gas Tank of Car | Example (5 minutes) In this example problem the overflow volume of gasoline is calculated for the case of cool gas (petrol) from an underground tank being put in the gas tank of a car that is parked in direct sunlight. The expansion of the gasoline and the expansion of the volume of the tank are calculated |

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Heat, Thermodynamics, Heat Engines | ||

Heat Specific Heat Latent Heat | Lecture (19 minutes) This video gives the physics definition of Heat. The video discusses the relationship between energy moving into and out of a system and the change in temperature of the system. The video discusses the relationship between energy moving into or out of a system and the change of phase of the system. This material relates to Chapter 14 of OpenStax College Physics. | |

Conduction Convection Radiation | Lecture (24 minutes) This video describes three modes of energy transfer: conduction, convection, radiation. The video explains what can lead to a higher value for heat for each of the three mechanisms. This material relates to Chapter 14 of OpenStax College Physics. | |

Calorimetry Aluminum Cup, Water, Lead | Example (5 minutes) This video shows the solution to a calorimetry problem. A hot lead object is placed in an aluminum cup that contains water. There is no ice in the system. The calorimetry equation has Q = mc Delta T for each object. The sum of the Q's is zero. The hot object gives up energy and has a decrease in temperature. The cooler objects receive energy and increase in temperature. The final temperature is calculated. The video makes some comments about inspecting the answer to see if it is reasonable. This material relates to Chapter 14 of OpenStax College Physics. | |

Calorimetry Aluminum Cup, Water, Ice, Lead | Example (9 minutes) This video shows the solution to a calorimetry problem. A hot lead object and ice are placed in an aluminum cup that contains water. The calorimetry equation has Q = mc Delta T for each object. The equation includes a mL term for the energy required to melt the ice. The sum of the Q's is zero. The hot object gives up energy and has a decrease in temperature. The cooler objects receive energy and increase in temperature. The final temperature is calculated. The video makes some comments about inspecting the answer to see if it is reasonable. This material relates to Chapter 14 of OpenStax College Physics. | |

Energy Loss Due To Conduction Wood, Styrofoam, Aluminium | Example (7 minutes) This video shows a simple calculation for energy loss due to conduction through a barrier. The barrier in this example is the four walls of a hypothetical home. The length, width, and thickness of the walls are given. The inside and outside temperatures are given in Fahrenheit. The length of time is given. This calculation ignores doors, windows, and the roof. | |

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First Law Thermodynamics, PV Diagram paths, Work | Lecture (28 minutes) This video discusses the First Law of Thermodynamics, Delta U = Q - W. The video discusses the PV diagram and four paths commonly encountered as systems move between states of U, T, P, V, and N. Isothermal, Adiabatic, Isobaric, and Isochoric paths are discussed. W = P x Change in Volume if pressure is constant. This material relates to Chapter 15 of OpenStax College Physics. | |

Second Law Thermodynamics, Heat Engines, Efficiency, Carnot Heat Engine | Lecture (18 minutes) This video discusses the Second Law of Thermodynamics, Heat Engines, Efficiency, and the Carnot Ideal Heat Engine. The Second Law of Thermodynamics is stated in various ways. The equations for calculating efficiency for an ordinary heat engine and a Carnot heat engine are explained. This material relates to Chapter 15 of OpenStax College Physics. | |

Heat Pump, Coefficient of Performance | Lecture (13 minutes) This video discusses the basics of a heat pump. The discussion context is delivering energy to the inside of a home in the winter. The equations for the coefficient of performance are given. The equations related to a refrigerator are not given. This material relates to Chapter 15 of OpenStax College Physics. | |

Adiabatic Expansion Calculate Delta U and Delta T | Example (4 minutes) This video shows how to calculate the change in internal energy and the change in temperature for an ideal gas system that undergoes an adiabatic expansion. This material relates to Chapter 15 of OpenStax College Physics. | |

PV Diagram, Work Done For Path, Area Enclosed | Example (5 minutes) This video shows a given set of paths on a Pressure Volume (PV) Diagram. The work for each path is calculated and the net work is calculated. The area enclosed by the paths is shown to be equal to the net work. | |

PV Diagram, Work Calculations Isobaric, Isochoric, Isothermal | Example (9 minutes) This video calculates the work done by an ideal gas system that has an isobaric, isochoric, and isothermal process. The individual work values are calculated. The net work is calculated and then checked by finding the area of a triangle that is a little larger than the actual enclosed area on the PV diagram. | |

PV Diagram, Work for Isothermal and Adiabatic Paths | Example (12 minutes) This video shows the calculations for work done as an ideal gas system undergoes isothermal and adiabatic paths. The system is returned to its starting condition (P V T) after the last process. The net work is calculated and checked using a rectangle on the PV diagram. | |

Simple Heat Engine Work, Efficiency | Example (2 minutes) This video shows how to calculate the work done by a simple heat engine and the efficiency of the heat engine. The amount of energy leaving the hot reservoir and the amount of energy delivered to the cold reservoir are given. This material relates to Chapter 15 of OpenStax College Physics. | |

Carnot Engine Efficiency, Work Done | Example (5 minutes) This video calculates the efficiency for a Carnot heat engine. The temperatures of the hot and cold reservoirs are given in Celsius and converted to Kelvin. The work done by the Carnot heat engine is calculated based on the given value for the energy leaving the hot reservoir. The efficiency and work done by a real heat engine are also calculated. This material relates to Chapter 15 of OpenStax College Physics. | |

Heat Pump Example Problem | Example (3 minutes) This video calculates the dollar value of the energy moved to the inside of a home by a heat pump. The dollar value of the work put into the heat pump and the coefficient of performance are given. The video also shows how to calculate the dollar value of the energy picked up from the cold reservoir. This material relates to Chapter 15 of OpenStax College Physics. | |

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Simple Harmonic Motion | ||

Springs, Hooke's Law, Simple Harmonic Motion | Lecture (16 minutes) This video discusses springs and simple harmonic motion. The terms displacement, force constant, Hooke's Law, amplitude, period, frequency, and restoring force are discussed. The video discusses why energy methods and not the four kinematic equations are used to solve spring problems. This material relates to Chapter 16 of OpenStax College Physics. | |

Simple Harmonic Motion, Horizontal Spring With Mass | Example (10 minutes)A spring is anchored at one end. A force of 9 N extends the spring 3 cm. A 2.2 kg mass is attached to the end of the spring. The mass is positioned 2 cm to the right of the equilibrium position and released from rest. These values are determined: maximum acceleration, max velocity, time to reach the equilibrium position, and max displacement left of the equilibrium position. | |

Mass Dropped Onto Vertical Spring | Example (16 minutes) In this example a mass is dropped onto a vertical spring. The mass of the object, the height fallen, and the spring constant are given. The speed at contact, equilibrium position of the spring, speed at equilibrium, and total compression of the spring are calculated. | |

Horizontal Spring With Mass | Example (10 minutes) A spring is anchored at one end. A force of 9 N extends the spring 3 cm. A 2.2 kg mass is attached to the end of the spring. The mass is positioned 2 cm to the right of the equilibrium position and released from rest. These values are determined: maximum acceleration, max velocity, time to reach the equilibrium position, and max displacement left of the equilibrium position. | |

Spring Cut In Half, New Force Constant | Example (5 minutes) This video shows how to determine the force constant, k, for a spring when the load and stretch of the spring are given. The video shows how to determine the new force constant when a spring is cut in half. | |

Determine Force Constant and Mass Attached to Spring | Example (6 minutes) This video shows how to determine two unknown quantities for a spring system when two period values are given. The solution is obtained by solving a system of two unknowns in two equations. | |

Pendulum, Uniform Circular Motion Shadow, Damped Harmonic Motion, Resonance | Lecture (17 minutes) This video describes the calculation for the period of a pendulum. The reason pendulum motion is not quite simple harmonic motion is explained. The video describes why the motion of the shadow of an object in uniform circular motion is simple harmonic motion. The video discusses damped harmonic motion and resonance. This material relates to Chapter 16 of OpenStax College Phyiscs. | |

Pendulum Clock, Length Increases, Determine Error in Time | Example (10 minutes) This video calculates the error in the time of a clock regulated by a pendulum when the length of the pendulum changes due to a change in temperature. When the length increases the clock "runs slow." The video shows that it is not necessary to know the length of the pendulum. | |

Pendulum Clock on Earth and Moon, Time Error | Example (5 minutes) This video shows how to calculate the error in the displayed time for a clock that is regulated by a pendulum when that clock is taken to the Moon. The smaller value for the acceleration of gravity on the Moon causes the pendulum to swing slower on the Moon. The clock on the Moon runs slow. | |

Resonance, Waves, Interference, Beats | Lecture (20 minutes) This video discusses resonance. If a force is applied to a system with a frequency equal to the natural frequency of the system the amplitude will increase. The video also discusses transverse and longitudinal waves, superposition, interference, and beats. This material relates to Chapter 16 of OpenStax College Physics. | |

Frequency for Standing Wave on a String and Harmonic | Example (5 minutes) This video shows how the determine the fundamental frequency, and frequency of the 2nd harmonic, for a string that is anchored at each end. The length, mass, and tension for the string are given. | |

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Sound | ||

Sound velocity, wavelength, frequency, loudness, decibel, Doppler Effect | Lecture (21 minutes) This video gives an introduction to the topic of sound. The relationship between speed of the wave, wavelength, and frequency is described and illustrated with a calculation. The decibel system of loudness is discussed and illustrated with two calculations. The concepts of the Doppler effect are discussed without any calculations. This material relates to Chapter 17 of OpenStax College Physics. | |

Noise Cancellation Headphones, Standing Waves, Harmonics | Lecture (15 minutes) This video gives a brief explanation of the operation of noise cancelling headphones. Most of the video is devoted to explaining the standing wave frequencies for a pipe closed at one end and a pipe open at both ends. A few comments are made about musical instruments. This material relates to Chapter 17 of OpenStax College Physics. | |

Sound Resonance Open and Closed Pipes | Example (7 minutes) This video shows how to solve problems for the case of a sound wave resonating in an open pipe and in a closed pipe. The speed of sound is calculated based on the temperature. A sketch is made to show where the nodes and antinodes are located. In one example the length of the pipe is determined. In the other example the frequency of the third harmonic is determined. | |

Speed of Sound and Air Temperature From Air Column Measurements | Example (5 minutes) The speed of sound and the air temperature are determined from lab data with an air column. The air column is open at the top end of the tube that is open. The length of the air column is adjusted by varying the amount of water in the tube. When the water level is at the proper level a loud sound is heard as a standing wave is set up in the air column. The speed of sound is related to the air temperature. | |

Calculate the Intensity When dB (Decibel) Value is Given | Example (5 minutes) This video calculates the intensity value for a sound when the decibel db is given. | |

Decibel Value When Distance To Source Changes | Example (7 minutes) The intensity value for sound at a given distance from a source is given. The decibel value is calculated. The receiver then moves to a different distance from the source. The decibel value is calculated in two different ways. | |

Distance to Storm from Thunder Time Delay | Example (7 minutes) This video calculates the distance to a thunderstorm based on the speed of sound and the time delay between seeing the lightning and hearing the thunder. | |

Doppler Shift For Sound Reflected From Moving Car | Example (8 minutes) This video determines the frequency shift in a sound wave that is reflected from a moving car. | |

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