AP EAMCET2007PhysicsCenter of Mass, Momentum and Collision
A rifle of 20 ~kg mass can fire 4 bullets per second. The mass of each bullet is 35 10⁻³ ~kg and its final velocity is 400 ~ms ⁻¹ . Then what force must be applied on the rifle so that it does not move backwards while firing the bullets ?
Options
- A80 ~N
- B28 ~N
- C-112 ~N
- D-56 ~N
Correct answer
D. -56 ~N
Step-by-step solution
From conservation of momentum aligned & M V+(4 m v)=0 V & =- 4 m v M =- 4 35 10⁻³ 400 20 = & -2.8 ~ms ⁻¹ aligned Force applied on the rifle, aligned F & = M V t =- 20 2.8 1 & =-56 ~N aligned