Question

A steel ball A of mass 20 kg moving with speed of 2m/s collides with another ball B of mass 10 kg which is initially at rest. After the collision A moves off with a speed of 1 m/s at an angle of 30°with its original dorection of motion. Determine the final velocity of B

Answer 1

Let, m₁= Mass of steel ball A

m₂= mass of steel ball B

v₁= initial velocity of body

v₂= final velocity of body

From conservation of momentum,

=> m₁v₁+m₂v₁=m₁v₂+m₂v₂

=> 20×2 + 10×0= 20×1cos30° + 10×v₂

=> 40 + 0= 20×(√3/2) + 10v₂

 => v₂=(40-10√3)/10

         = 2.267 m/s