Question

A block of mass 4 kg moving with a velocity of 10 m/s collides elastically with a block of mass 5 kg, which is at rest. If after collision blocks deflected at angle 30° and 60° respectively, then find out the velocities; of the block after collision.

Answer 1

Given;
m₁ = 4 kg, u₁ = 10 ms^-1; m₂ = 5 kg,
u₂ = 0; θ₁ = 30°, θ₂ = 60°;
u₁ = ?; u₂ = ?
Applying the law of conservation of momentum in A-direction, we have

Now applying the law of conservation of momentum in Y-direction, we get

Now substituting the value of v₂ in Eq (2), we get