Question

After a hold up, Robin Banks flees in his 1575 kg getaway car at 20 m/s. He crashes into a 45 kg highway barrel which is at rest. If Robin Bank’s car moves at 18.9 m/s after the collision, how fast does the barrel move after being hit?

Answer 1

v = 38.9 m/s

Step-by-step explanation:

Answer 2

v = 38.5 m/s

Step-by-step explanation:

P1 = P2 (conservation law of linear momentum)

(1575 kg)(20 m/s) + (45 m/s)(0) = (1575 kg)(18.9 m/s) + 45v

Solving for v

v = 38.5 m/s