ASTR 100 Lecture Notes - Lecture 10: Angular Momentum, Angular Velocity, Vise

• School: University of Maryland
• Department: Astronomy
• Course: ASTR 100
• Professor: Sylvain Veilleux

Document Summary

You can only transform them from one of the following forms to another: The total momentum of interacting objects cannot change unless an external force is acting upon them. Interacting objects exchange momentum through equal and opposite forces. Ex: a pool ball collision between a stationary ball and a ball with momentum. The ball with momentum loses its momentum and the stationary ball moves off with the transferred momentum of the first ball. Angular momentum is mass times velocity times radius. The rotational momentum of an object cannot change unless a torque (twisting force) acts upon it. Earth does not experience a twisting force as it rotates the sun so its rotation and orbit will continue on indefinitely. Angular momentum explains why objects with a smaller radius spin faster. By pulling her arms in, a figure skater can increase her angular velocity and thus remain in the air for longer.