Question

If a machine gun fires $n$ bullets per second each with kinetic energy $K$, then the power of the machine gun is

• A. $n{K}^2$
• B. $\frac{K}{n}$
• C. $n^{2}K$
• D. $nK$

Answer 1

Answer: (D)

Power $=\frac{\text{ total work done }}{\text{ time }}$
$=\frac{\frac{1}{2}M{v}^2}{t}=\frac{1}{2}\left(m{v}^2\right)n\left(\because \frac{M}{t}=mn\right)$
$=kn\left[\because KEK=\frac{1}{2}m{v}^2\right]$