A sphere of redius `R` is ibn contact with a wedge. The point of contact is `( R)/(5)` from the ground as shown in figure.Wedge is moving with velocity `20 m s^(-1)` towards left then the velocity of the sphere at this instant will be

Options

A. `20 m s^(-1)`
B. `15 m s^(-1)`
C. `16 m s^(-1)`
D. `12 m s^(-1)`

Answer

B

Explanation

`cos theta = (4 R//5)/( R) = 0.8`

`:. (nu_(1))/(nu_(2)) = tan theta = tan 37 ^(@) = (3)/(4)`

`:. nu_(1) = (3)/(4) nu_(2) = (3)/(4) xx 20`
`= 15 m//s