1) A system of particles is known to have a total kinetic energy of zero. What can you say about the total momentum of the system? 2) A bowling ball and a Ping-Pong ball are rolling toward you with the same momentum. If you exert the same force to stop each one, which takes a longer time to bring to rest?
a) the bowling ball
b) same time for both
c) the ping-pong ball
d) impossible to say
3) A cannon sits on a stationary railroad flatcar with a total mass of 1000 kg. When a 10-kgcannonball is fired to the left at a speed of 50 m/s, what is the recoil speed of the flatcar?