Highly selective Backlog Qs for JEE MainPhysicsCenter of Mass, Momentum and Collision
A body of mass 4 m is lying in x - y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass m move perpendicular to each other with equal speeds υ . The total kinetic energy generated due to explosion is:
Options
- Am υ 2
- B3 2 m υ 2
- C2 m υ 2
- D4 m υ 2
Correct answer
B. 3 2 m υ 2
Step-by-step solution
The total momentum of the system will be conserved before and after explosion. Then, p i = p f O = m v i ^ + m v j ^ + 2 m v → v → = - v 2 i ^ - v 2 j ^ v → = v 2 Total kinetic energy generated due to explosion is K E = v 2 m v 2 + v 2 m v 2 + v 2 2 m v 2 2 = m v 2 + m v 2 2 = 3 2 m v 2