Question

A bullet of mass 0.02 kg is moving with a speed of 10 ms^–1. It can penetrate 10 cm of a wooden block, and comes to rest. If the thickness of the target would be 6 cm only, find the K.E. of the bullet when it comes out.

Answer 1

For x = 10 cm = 0·1 m, Fx = 1/2 mv₁² - 1 J

∴  F = 10 N

= 1 – 0·6 

= 0·4 J