Question

A bullet of mass 10 gm moving with a horizontal velocity 100m/s passes through a wooden block of mass 100 gm. The block is resting on a smooth horizontal floor. After passing through the block the velocity of the bullet is 10m/s. the velocity of the emerging bullet with respect to the block is 1) 10 m/s 2) 9 m/s 3) 1 m/s. 4) 5 m/s

Answer 1

simply use the law of conservation of momentum...

momentum before collision=momentum after collision.....(coz,only internal forces are acting)

let the velocity of block be v

then

10×100+0=10×10+100×v

900=100v

v=9

since the velocity of bullet is 10m/s and that of block is 9m/s

respective velocity of bullet=10-9=1m/s

hope it helps you