A machine gun fires six bullets per second into a target. The mass of each bullet is 3 g and the speed 500 m/s. The power delivered to the bullets is 

Options

A. 1.5 kW
B. 2.25 kW
C. 0.75 kW
D. 375 W

Answer

B

Explanation

The power delivered is the work done per second which again is equal to the total kinetic energy of the six bullets fired per second.
Hence power P = 6 (kinetic energy of each bullet)
`= 6[1/2 xx 3 xx 10^(-3) xx (500)^2] J//s = 2250 W = 2.25 W`.