Question

A small ball with a mass of 0.6 kg and a velocity of 12 m/smetre per second hits another ball with the same mass. The first ball stops moving, and the second ball then moves forward and hits a third ball with a mass of 0.2 kgkilo gram. If the system is closed, what is the velocity of the third ball? (1 point)
Responses

1.44 m/s2


30 m/s2


36 m/s2


4 m/s2

Answer 1

Initial momentum = 0.6 kg × 12 m/s = 7.2 kg·m/s.
If the second ball transfers all momentum to the third (closed system), 0.2 kg × v3 = 7.2, so v3 = 7.2 / 0.2 = 36 m/s.

(Answer: 36 m/s — option "36 m/s2" given, units should be m/s.)