Question

When a bullet leaves a barrel of a rifle, it is moving 640 m/s. If the barrel is 1.20 m long, and if the bullet undergoes constant acceleration while within the barrel, how long after the rifle is fired will the bullet emerge from the end of the barrel?

Answer 1

a=(V^2-Vo^2)/2d = (640^2-0)/2.4=170,667
m/s^2.

V = Vo + a*t
t=(V-Vo)/a = (640-0)/170,667=0.00375 s.
= 3.75 ms.