JEE Main20208 Jan 2020Morning ShiftPhysicsCenter of Mass, Momentum and CollisionActual
A body A of mass m = 0.1 k g has an initial velocity of 3 i ^ m s - 1 . It collides elastically with another body B of the same mass which has an initial velocity of 5 j ^ m s - 1 . After the collision, A moves with a velocity v → = 4 i ^ + j ^ m s - 1 . The energy of B after the collision is written as x 10 J . The value of x is
Correct answer
0
Step-by-step solution
Using the principle of conservation of linear momentum 0 . 1 × 3 i ^   +   0 . 1 × 5 j ^   =   0 . 1 × 4 i ^ + j ^   +   0 . 1 × v → v → = - i ^   +   j ^   m   s - 1 v = v → = 2   m   s - 1 K B = 1 2 × 0 . 1 × v 2 = 1 10   J x = 1