A machine gun of mass 10 kg fires 20 g bullets at the rate of 180 bullets per minute with a speed of 100 m s⁻¹ each. The recoil velocity of the gun is:
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A machine gun of mass 10 kg fires 20 g bullets at the rate of 180 bullets per minute with a speed of 100 m s⁻¹ each. The recoil velocity of the gun is:

G1 Physics · Accepted Answer

Bullets fired per second = 180/60 = 3. Momentum carried per second = 3×0.020×100 = 6 kg m s⁻¹. Equating momentum gives 10v = 6, so recoil speed v = 0.6 m s⁻¹.