Question

A bullet traveling at 350 m/s hits a tree, penetrating 0.125 m into the tree before stopping. The mass of the bullet is 0.200 kg. Treat the force the tree exerts on the bullet to stop it as a constant force. a) How big is the acceleration the bullet experiences when it hits the tree

Answer 1

Answer:

$-4.9\cdot 10^5 m/s^2$

Explanation:

The motion of the bullet is a uniformly accelerated motion, therefore we can find its acceleration by using the following suvat equation:

$v^2-u^2=2as$

where

v is the final velocity

u is the initial velocity

a is the acceleration

s is the distance covered

For the bullet in this problem:

u = 350 m/s is the initial velocity of the bullet

v = 0 is the final velocity (the bullet comes to a stop)

s = 0.125 m is the stopping distance of the bullet

Therefore, by solving the equation for a, we find its acceleration:

$a=\frac{v^2-u^2}{2s}=\frac{0^2-350^2}{2(0.125)}=-4.9\cdot 10^5 m/s^2$

And the negative sign tells that the direction of the acceleration is opposite to that of the velocity.