Question

A bullet of mass 20 g is horizontally fired with a velocity of one 50 m/s from a piston of mass 2 Kg.what is the recoil velocity of the pistol??

Answer 1

Let,

mass of bullet = m = 20 g = 0.02 kg

mass of piston = M = 2 kg

Initial velocity of mass+ bullet = 0

Final velocity of bullet =  v = 50 m/s

Final velocity of pistol = V = ?

According to law of conservation of momentum,

0 ( M+m) = MV + mv

- 2 V = 1

V = -1/2 m/s = -0.5 m/s

Hope this helps!