A smooth ball `'A'` moving with velocity `'V'` collides with another smooth identical ball at rest. After collision both the balls move with same speed with angle between their velocities `60^(@)`. No external force acts on the system of balls.

The speed of each ball after the collision is

Options

A. `(v)/(2)`
B. `(v)/(3)`
C. `(V)/(sqrt(3))`
D. `(2V)/(sqrt(3))`

Answer

C

Explanation

From conservation of momentum
`mv=mv' cos 30^(@)+mv' cos 30^(@)`
`:. V' =(v)/(2 cos 30^(@))=(v)/(sqrt(3))`