On a smooth carrom board. A coin located at `(4,6)` is moving in negative `y-`direction with speed `3m//s` is being hit at that point by a striker moving along negative `x-` axis . The line joining centre of the coin and striker just before the collision is parallel to `x-` axis. After collision the coin goes into the hole located at origin. Mass of the striker and the coin is equal. Considering the collision to be elastic, find the velocity `(` in vector form `)` of the stricker before the collision and after the collision.

Options

A. `(1.2, 0)`
B. `(2, 0)`
C. `(3, 0)`
D. None of these

Answer

B

Explanation

Monentum of the coin perpendicular to the common normal remains constant.

`:. V_(y) = -3` (constant)
`v_(y)t = -6 rArr t = 2 sec` & `v_(x) t = -4`
`v_(x) = -2 m//s`
Which is given by stricker.
So initial velocity of stricker = `2ms^(-1)`
Final velocity of the striker `= 0`