Circular Motion & Rotation

Uniform Circular Motion

Loss of Centripetal Force

RealVideo®
6:00 minutes (6:21 - 12:21)

Causes of centripetal acceleration, and demonstration of straight path motion after loss of centripetal force.

Instructor: Prof. Walter Lewin
Prior Knowledge: Circular Motion (Beginning of V5)

Centrifuges

RealVideo®
4:48 minutes (17:17 - 22:05)

Reasoning showing why centrifuges work, with demonstration of lettuce in a collander.

Instructor: Prof. Walter Lewin
Prior Knowledge: Centripetal Force (6:21 of V5)

Centrifuging a Solution

RealVideo®
9:56minutes (32:11 - 42:07)

Explanation of how small particles sink to side in a centrifuge; demo of centrifuging AgCl.

Instructor: Prof. Walter Lewin
Prior Knowledge: Centrifuges (17:17 of V5)

Water in a Bucket

RealVideo®
8:39 minutes (42:07 - 50:46)

Demonstration of water in a spinning bucket feeling artificial gravity upwards.

Instructor: Prof. Walter Lewin
Prior Knowledge: Centrifuges (17:17 of V5)

Mechanical Energy and Centripetal Force

RealVideo®
7:34 minutes (23:37 - 31:11)

Example and demonstration of a ball in a looping rollercoaster; proof that h≥2.5R for ball to make it around.

Instructor: Prof. Walter Lewin
Prior Knowledge: Conservation of Energy (17:00 of V11)

Torque & Rotational Statics

RealVideo®
2:03 minutes (19:03 - 21:06)

Demonstration of weight placed on ladder near critical angle at various positions.

Instructor: Prof. Walter Lewin
Prior Knowledge: Ladder Stability II (9:23 of V25)

Equilibrium and Center of Mass

RealVideo®
9:36 minutes (33:54 - 43:30)

Statics of a hanging object; position of center of mass for equilibrium; demonstrating the stability of several small objects.

Instructor: Prof. Walter Lewin
Prior Knowledge: Static Equilibrium (Beginning of V6)

Rope Walker

RealVideo®
4:35 minutes (43:30 - 48:05)

Discussion of stability of rope walker with objects suspended to lower center of mass; brief demonstration of rope walker on zip line.

Instructor: Prof. Walter Lewin
Prior Knowledge: Equilibrium and Center of Mass (33:54 of V25)

Rotational Kinematics & Dynamics

Ball in Circular Well

RealVideo®
4:36 minutes (46:53 - 51:29)

Demonstration of failure of simple harmonic motion for ball in circular well; calculation of T does not agree with SHM.

Instructor: Prof. Walter Lewin
Prior Knowledge: Oscillation in Circular Well II (32:46 of V13)

Energy from Spindown

RealVideo®
8:49 minutes (20:52 - 29:41)

Demo of converting rotational KE to linear KE from car flywheel; rotational KE of Sun, Earth and potential for use.

Instructor: Prof. Walter Lewin
Prior Knowledge: Rotational Kinetic Energy

Dependence of Roll on Inertia

RealVideo®
5:22 minutes (8:42 - 14:04)

Proof that acceleration is independent of M, R; acceleration for various geometries, with demonstration.

Instructor: Prof. Walter Lewin
Prior Knowledge: Acceleration of a Pure Roll (Beginning of V24)

Angular Momentum & its Conservation

Ice Skater's Delight

RealVideo®
7:58 minutes (17:36 - 25:34)

Angular momentum conservation calculation and demonstration for spinning person, with arms outstretched and pulled in.

Instructor: Prof. Walter Lewin
Prior Knowledge: Conservation of Angular Momentum (8:18 of V20)

Motion of a Rod After Impulse

RealVideo®
11:30 minutes (14:10 - 25:40)

Speed of center of mass and angular velocity of rod after impulse at non-CM point, using two different origins; demonstration of this motion.

Instructor: Prof. Walter Lewin
Prior Knowledge: Angular Momentum of Spinning Rod (7:36 of V21)