Author Question: A 5000-kg freight car crashes into a 10,000-kg freight car at rest. They couple upon collision and ... (Read 120 times)

armygirl · **on:** Jul 29, 2018

A 5000-kg freight car crashes into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg freight car?

A) 4 m/s
B) 5 m/s
C) 6 m/s
D) 8 m/s
E) none of the above

Question 2

Two identical freight cars roll without friction towards each other on a level track. One car rolls at 2 m/s and the other car rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of

A) 0.5 m/s.
B) 0.33 m/s.
C) 0.67 m/s.
D) 1.0 m/s.
E) none of the above