# How to find the force of a bullet?

A bullet of mass 0.0018 kg initially moving at 486 m/s embeds itself in a large fixed piece of wood and travels 0.54 m before coming to rest. Assume that the acceleration of the bullet is constant.

What force is exerted by the wood on the bullet? (in Newtons)

Relevance

There is no force from the wood, it only provides absorption and distribution of the power inherent it the projectile. It is a passive resistance. This resistance can be measured by various means and instruments that take into account target mass. vs impact velocities.....I think.

• F = ma

the mass of the bullet is 0.0018kg

the acceleration is found by solving the following formula for a

v² = u² + 2as

a = (v² - u²)/2s

the final velocity (v) = 0

the initial velocity (u) = 486m/s

the distance (s) = 0.54m

Solve this for a then solve the initial equation.

• F=ma. Repeat the mantra...

F=ma. F=ma.

Bullet. Know m. Check.

Goes from 486 m/s to 0 in 0.54m. Use the V² formula. Know now a. Check.

F=ma. Now know force.