Question

A hammer of mass $500g,$ moving at $50{ms}^{-1},$ strikes a nail. The nail stops the hammer in a very short time of $0.01s.$ What is the force of the nail on the hammer?

Answer 1

Given : Mass of the hammer, $M=500g$ $=0.5kg$

Initial velocity of the hammer, $u=50$ $m{s}^{-1}$

Final velocity of the hammer, $v=0$

Time taken, $t=0.01s$

Thus change in momentum of the hammer, $\Delta P=mv-mu$

$\Delta P=0-0.5\times 50=-25$ $kg$ $m{s}^{-1}$

Force of the nail on hammer, $|F|=\frac{|\Delta P|}{t}=\frac{25}{0.01}=2500N$