Mass of the hammer, m= 500 g = 0.5 kg
Initial velocity of the hammer, u= 50 m/s
Time taken by the nail to the stop the hammer, t = 0.01 s
Velocity of the hammer, v= 0 (since the hammer finally comes to rest)
From Newton's second law of motion:
The hammer strikes the nail with a force of - 2500 N. Hence, from Newton's third law of motion, the force of the nail on the hammer is equal and opposite, i.e., +2500 N.