Question

A bullet of mass 50 gram moving with an initial velocity 100 m/s, strikes a wooden block and comes to rest after penetrating a distance 2 cm in it. calculate: (i)initial momentum of the bullet, (ii)final momentum of the bullet, (iii)retardation caused by the wooden block, and (iv)resistive force exerted by the wooden block.

Answer 1

Coordinate for uniformly accelerated motion equals:                                                                                                                                                                                      = 0 − 2 2 0 - initial velocity of the bullet –deceleration − time Velocity for uniformly accelerated motion equals: = 0 − If bullet comes to rest: = 0 => = 0 Therefore, from the equation for coordinate: = 0 0 − ( 0 ) 2 2 = 0 2 2 deceleration equals: = 0 2 2 = (100 ) 2 /2 And, finally, retardation equals: = = 0 2 2 = 0.05 ∗ (100 ) 2 2 ∗ 0.02 = 12500 = 12.5                                                                                           Answer: 12500