A ball is dropped on a smooth inclined plane and is observed to move horizontally after the impact. The coefficient of restitution between the plane and ball is e. The inclination of the plane is

Options

A. 1
B. `3/4`
C. `1/2`
D. `1/4`

Answer

B

Explanation

C to D `v_(2) = sqrt(2gx) = gt` `therefore = (v_(2))/(g)`
From A to B, time willl become two times.
Applying `S = ut+1/2at^(2)` in vertical direction, we have
`-x = (ev_(2)(2t) -1/2xx g xx(2t)^(2)`
`-x = (2ev_(2)^(2))/(g) - (2v_(2)^(2)) rArr -x = 2e(2x)-2(2x)`
`therefore e=3/4`