Immediately after being struck by a hammer the nail mass of

Immediately after being struck by a hammer, the nail (mass of 50 g) has a velocity of 50 m/s. The total frictional force is 62.5 kN. How far does the nail move before it comes to a stop?

Solution

Kinetic energy of nail = 1/2mV^2 = 1/2 * .05 * 50*50 = 62.5 J

Work done by frictional force = 62.5 * 10^3 * x

where x is displacement of nail

now accroding to conservation of energy 62.5 *10^3 x= 62.5J

x= 1*10^-3 m ,