PHYS 121 Lecture 23: Energy and Interactions I
Document Summary
All diagrams taken from "l23_energy_and_interactions. pdf" on the course canvas website. If the center of mass motion is zero, all the kinetic energy is convertible ke (totally inelastic collisions: a galaxy with a nonzero center of mass velocity has ke and translational ke, because the particles have additional velocity. In an isolated system, the center of mass velocity doesn"t change. If change in ke = 0 it is elastic. If change in ke is negative it is inelastic. If change in ke > 0 it is an explosion. Quiz: consider the following two totally inelastic collisions between cart 1 and cart 2. Both carts have an inertia of 0. 25 kg: cart 1 moves to the right at 0. 20 m/s and cart 2 is at rest. Cart 1 moves to the right at 0. 10 m/s and cart 2 moves to the left at 0. 10 m/s.
