Momentum: Review

Question 1

How do you tell if there is a momentum problem?

Answer 1

A collison occurs

Question 2

Derive p=Ft from F=ma

Answer 2

F=ma = m v/t
m v/t = m v_f - v_i/t
mv_f -mv_i/t = p/t
P=Ft

Question 3

Which has a greater change in momentum:
1. Hitting something and stopping
2. Hitting something and bouncing backwards

Answer 3

Hitting something and bouncing backwards

Question 4

How to calculate impulse from a Force/Time graph

Answer 4

Area under curve

Question 5

Energy problem vs. Momentum problem

Answer 5

If the number of objects stay the same, it is an energy problem
If the number of objects change or they bounce, it is a momentum problem

Question 6

Conservation of Momentum

Answer 6

p_i = p_f

Question 7

Elastic collisions

Answer 7

Objects bounce perfectly
Momentum and kinetic energy is conserved

Question 8

Inelastic collisions

Answer 8

Objects collide and stick together
Momentum is conserved but kinetic energy is not
If perfectly inelastic, the final velocities are the same