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. one
B. four
C. two
D. three

Answer

D

Explanation

u=velocity of bullet
`(dm)/(dt)` =Maa fired per second by the gun
`(dm)/(dt)`=Mass of bullet `(m_(B)` x Bullets fired per sec `(N)` .
Maximum force that man can exert `F=u((dm)/(dt))` .
:. `F=uxxm_(a)xxN` .
`implies N=(F)/(m_(B)xxu)=(144)/(40xx10^(-3)xx1200)=3` .