Discussion Forum

A man holding a rifle (mass of person and rifle together is 100kg) stands on a smooth surface and fires 10 shots horizontally in 5 sec. Each bullet has a mass of 10 g with a muzzle velocity of 800 ms^-1 . The velocity which the rifleman attains after firing 10 shots will be

Answer:

Explanation:

According to the law of conservation of momentum,

P_(Initial) =  P_(final)

mu₁ + Mu₂ = mv₁ + Mv₂ 

0 + 0 = 10×10×10^-3×800 +[100- 10 x 10 x $10^{-3}$]v

v = $\frac{-800}{999}$ = -0.8 m/s

Negative sign indicates that the velocity is opposite to the direction of bullets