Question

A machine gun fires $240$ bullets $perminute$ with a certain velocity. If the mass of each bullet is $10gm$ and the power of the gun is $7.2kW$, the velocity with which each bullet is fired must be:

• A. $300m/s$
• B. $600m/s$
• C. $1200m/s$
• D. $60m/s$

Answer 1

The correct option is B $600m/s$

$Power=\frac{\Delta KE}{t}$
$⟹7.2\times {10}^3=\frac{240\times \frac{1}{2}\times {10}^{-2}\times v^2}{60}$

$\therefore v=600m/s$