Question

Two rifles fire the same number of bullets in a given interval of time. The second riffle fires bullets of mass twice that fired by the first, and with a velocity that is half that of the first. The ratio of the power of first rifle to that of second one is :

• A. 1:4
• B. 4:1
• C. 1:2
• D. 2:1

Answer 1

The correct option is D 2:1

Power of first riffle ($P_I$) $=\frac{\frac{1}{2}m{v}^2}{t}$

Power of second riffle ($P_{II}$)$=\frac{\frac{1}{2}\times 2m\times \frac{v^2}{4}}{t}$

$\Rightarrow \frac{P_I}{P_{II}}=2:1$