Question

A machine gun fires $420$ bullets $perminute$. The velocity of each of the bullets is $300m{s}^{-1}$ and the mass of each bullet is $1gm$. The power of machine gun is:

• A. $315W$
• B. $315000W$
• C. $630W$
• D. $3150W$

Answer 1

Answer: (A)

$315W$

$P=\frac{WorkDone}{t}$

$=\frac{420\times (\Delta KE{)}_{onebullet}}{t=1min}$
$=\frac{420\times \frac{1}{2}\times {10}^{-3}\times (300{)}^2}{60}$
$=315W$