Question

a bullet of mass 20g is fired from a rifle of 8kg with a velocity of 100ms-1. the velocity of recoil of the rifle is : give answer with solution in photo.

Answer 1

Heya.......!!!!


This question can be solved by " Conservation of Momentum . :

=> m1v1 = M2V2

=> 20/1000 × 100 = 8 × V2

=> 2 = 8×V2

=> V2 = 2/8 m/s

=> V2 = 1/4 = 0.25 m/s .



Hope It Helps You ^_^

Answer 2

Apply conservation of linear momentum

Initial momentum = Final momentum
0 = mu + Mv

v = - mu / M
= -(0.02 kg × 100 m/s) / (8 kg)
= -0.25 m/s
(-ve sign indicates that rifle moves in the direction opposite to that of billet.)

∴ Recoil Velocity of rifle is 0.25 m/s