Question

A bullet with a mass of 4.69 g and a speed of 839 m/s penetrates a tree horizontally to a depth of 3.98 cm. Assume that a constant frictional force stops the bullet. Calculate the magnitude of this frictional force. Try energy considerations

Answer 1

Answer:

Force will be equal to 41474.723 N

Explanation:

We have given mass of the bullet $m=4.69gram=4.69\times 10^{-3}kg$

Speed of the bullet $v=839m/sec$

So kinetic energy $KE=\frac{1}{2}mv^2=\frac{1}{2}\times 4.69\times 10^{-3}\times 839^2=1650.694J$

Depth is given d = 3.98 cm = 0.0398 m

Let the horizontal force is F

So from work energy theorem

$Fs=1650.694$

$F\times 0.0398=1650.694$

$F=41474.723N$