Kinematics - 28th Jan'16


A large rectangular box ABCD falls vertically with an acceleration ‘a’. A toy gun fixed at ‘A’ and aimed towards C fires a particle P

(a) P will hit C if !!a=g!!

(b) P will hit the roof BC if !!a>g!!

(c) P will hit the wall CD or the floor AD if !!a< g!!

(d) Can’t say


Super impose an upward acceleration 'a' on the system. The box becomes stationary. The particle has an upward acceleration 'a' and a downward acceleration 'g'.

If !!a=g!!, the particle has no acceleration and will hit 'C'.

If !!a>g!!, the particle has a net upward acceleration and will hit the roof BC.

If !!a< g!!,the particle has net downward acceleration nad will hit the wall CD or the floor AD.

Therefore, options (a),(b) and (c) are correct.