Question

A 10g riffle bullet acquires a speed of 400m/s in traversing a barrel 50cm long. Find the average

acceleration and the accelerating force.

Answer 1

The average acceleration

$$a=\frac{v_f^2-v_i^2}{2d}=\frac{0^2-400^2}{2*0.5}=-1.6*10^5\:\rm m/s^2$$

The magnitude of the force

$$F=ma\\ =0.01*1.6*10^5=1600\:\rm N$$