Two girls of equal mass `m` jump off from the border line of a stationary carriage of mass `M` with same horizontal velocity `u` relative to the carriage in same direction. Neglect the effect of friction. Mark correct options.

Options

A. They will impart greater velocity to the carriage by jumping of simultaneously
B. They will impart greater velocity to the carriage by jumping one after the other
C. They will impart same velocity to the carriage in whatever manner they jump off.
D. Insufficient data to reply

Answer

B

Explanation

Ans.(2)
When girls jump one by one total velocity of the system will be more (because from conservation of momentum, velocity of car in this case will be
`u_(car)=u((1)/(M+2m)+(1)/(M+m))m` instead of
`m u((1)/(M+2m)+(1)/(M+2m))` when they jump simultaneously.