A machine gun fires 240 bullets per minute. If the mass of each bullet is 10 g and the velocity of the bullets is `600 ms^(-1)`, then find power (in kW) of the gun.

Options

A. 12
B. 72
C. 7.2
D. 4.32

Answer

C

Explanation

v = u + at but u = 0 and t = T
`therefore v = aT " " therefore a=(v)/(T) " "` ….(1)
and velocity of the body after times t is given by
`v'=0+at=(vt)/(T)`
`therefore` Power `=F xx v'=mav'`
`=m xx(v)/(T)xx(vt)/(T)=(mv^(2)t)/(T^(2))`