A 15,0 g bullet is accelerated in the barrel of a 72,0 cm long rifle to a speed of 780 m/s.

Question

With the relationship between work and energy, find the power exerted on the bullet while it's being accelerated.

Answer 1

First, find the energy as the bullet leaves the barrel: E = 1/2 * m * v^2

Power is the rate of transfer of energy: P = E/t Joules /sec. We can get the time from the average velocity and the length of the barrel.