A machine gun fires a bullet of mass 40 g with a velocity `1200 ms^-1`. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can be fire per second at the most?

Options

A. two
B. four
C. one
D. three

Answer

D

Explanation

u = velocity of bullet
`(dm)/(dt) `= mass fired per second by the gun , `(dm)/(dt)` = mass of bullet `(m_(B)) xx` bullets
fires per sec (N)
Maximum force that man exert, `F = u ((dm)/(dt)) :. F = u xx m_(B) xx N`
`implies N = (F)/(m_(B) xx u) = (144)/(40 xx 10^(-3) xx 1200) = 3`