Consider elastic collision of a particle of mass m moving with a velocity u with another particle of the same mass at rest. After the collision the projectile and the struck particle move in direction making angles `theta_(1)` and `theta_(2)` respectively with the initial direction of motion. The sum of the angles. `theta_(1)+theta_(2)`, is

Options

A. `45^(@)`
B. `90^(@)`
C. `135^(@)`
D. `180^(@)`

Answer

B

Explanation

If the masses are equal and target is at rest and after collision both masses moves in different direction. Then angle between direction of velocity will be `90^(@)` , if collision is elastic.