Question

A hammer of mass 50 kg moving at 50 m/s strikes a nail. The nail stops the hammer in a very short time of 5 sec. What is the force of the nail on the hammer​

Answer 1

Mass of the hammer (m) = 500 g = 0.5 kg

The initial velocity of the hammer (u) = 50 m/s

The nail takes time to stop the hammer (t) = 0.01 s

The velocity of the hammer (v) = 0 (since the hammer finally comes to rest)

From Newton’s second law of motion

f = m (v – u) / t

Where f = force

f = 0.5 × (0 – 50) / 0.01

f = -2500 N

-ve sign indicates the force of the nail on the hammer moving in the opposite direction to that of hammer movement.

Answer 2

Step-by-step explanation:

The force of nail on the hammer

F=

Time

Change in momentum of hammer

F= m(v−u) = 0.010.5(0−50) =−2500N

Negative sign denotes that the force of nail on the hammer is acting in the direction opposite to that of motion of hammer.