Question

Two identical billiard balls undergo an oblique elastic collision. Initially, one of the balls is stationary. If the initially stationary ball after collision moves in a direction which makes an angle of `37^(@)` with direction of initial motion of the moving ball, then the angle through which initially moving ball will be deflected is
A. `37^(@)`
B. `60^(@)`
C. `53^(@)`
D. `gt53^(@)`

Answer 1

Correct Answer - C
When two indentical balls undergo elastic oblique collisions with one of them stationary, the after collision they will move at right angles to each other.
Alternative method I: Just like in previous question, you can proceed using centre of mass frame of reference.
Alternative method II: Using basic equation of conservation of momentum, conservation of energy and coefficient of restitution, you can have the desired result.