Question

A bullet of mass 50 g is fired from a 5 kg gun with a velocity of 1 km/sec. The speed of recoil of the gun is:

• A. 5 m/s
• B. 1 m/s
• C. 0.5 m/s
• D. 10 m/s

Answer 1

Answer: (D)

10 m/s

Answer 2

Applying law of conservation or momentum $mv\text{ }=\text{ }m\upsilon$ Here, mass of bullet $m=50\text{ }g=0.05\text{ }kg$ velocity of bullet $=1\text{ }km\text{/}sec=1000\text{ }m\text{/}sec$ mass of gun $m=5kg$ or $0.05\times 1000=5v$ or $v=\frac{0.05\times 1000}{5}$ so, $v=10\,m\text{/}s$