Question

A particle A suffers an oblique elastic collision particle `B` that is at rest initially. If their masses with a are the same, then after the collision
A. their `KE` may be equal
B. A continues to move in the original direction while `B` remains at rest
C. they will move in mutually perpendicular directions
D. A comes to rest and `B` starts rections moving in the direction of the original motion of `A2`

Answer 1

Correct Answer - A::C::D
As masses are equal and collision elastic
Therefore velocity along line of impact gets exchane and velocity perpendicular to line of impact remains unchanged.
If `alpha=45^(@)` the their speed will be same after collision, hence `KE` will be same.