Question

calculate the recoil velocity of a 4kg gun which shoots a 0.05lg bullet with speed of 280m/s

Answer 1

By momentum conservation
Mv=mV
4×v=280×0.05
v=70×0.05
v=3.5m/s
The recoil velocity is 3.5m/s

Answer 2

Mass of gun is 4 kg.

Mass of bullet is 0.05 g.

Velocity = 280 m/s.

U1=u2= 0

V1=280 v2 ?

By law of conservation of momentum

= M1u1 +M2u2= M1v1+ M2v2

= 0= 0.05×280 +4v

-4v= 14

So, v= 14/-4

= -7