Question

A hammer of mass 300g, moving of 75m/s strikes a nail. The nail stops in a very short time of 3×10`2 seconds. what is the change in momentum and the force exerted by nail on hammer?

Answer 1

Given:

Mass of hammer = 300 g

Velocity of hammer = 75 m/s

Time in which it stops = 3 × 10^(-2) sec.

To find:

• Change in Momentum

• Force exerted by hammer on nail.

Calculation:

Change in momentum of hammer can be calculated from the product of mass of hammer with the change in velocity of the hammer.

$\Delta P = m \times (\Delta v)$

$= > \Delta P = 0.3 \times (0 - 75)$

$= > \Delta P = 22.5 \: kgm {s}^{ - 1}$

Force is originally defined as the rate of change of momentum with respect to time.

$force = \dfrac{\Delta P}{\Delta t}$

$= > force = \dfrac{22.5}{3 \times {10}^{ - 2} }$

$= > force = 7.5 \times {10}^{2}$

$= > force = 750 \: N$

So , force exerted by hammer on nail is 750 N.