A hammer of mass `500g`, moving at `50m//s`, strikes a nail. The nail stops the hammer in a very short time of `0.01 s`. What is the force of the nail on the hammer?

Explanation

Mass of hammer, m = 500 g = 0 . 5 kg
Initial velocity of hammer , ` u = 50 m s^(-1)`
Final velocity of hammer , v = 0 and time , t = 0 . 0 1 s
`:. ` Acceleration of the hammer,
`a = ( v - u)/( t) = (0 - 50)/( 0 . 0 1) = - 5000 m s^(-2)`
`:.` Force applied by the hammer on nail
`F = ma = (0 . 5) xx (- 5000) = - 2500 N`
The hammer strikes the nail with a force of - 2500 N. By Newton.s third law of motion , nail will exert an equal and opposite force on the hammer
`:.` Force applied by the nail on hammer = 2500 N