A uniform sphere of weight `w` and radius `3m` is being held by a string of length `2m` , attached to a frictionless wall as shown in the figure. The tension in the string will be `:`

Options

A. `5 w//4`
B. `15 w//4`
C. `15 w//16`
D. none of these

Answer

A

Explanation

From geometry

`cos theta = (3)/(5) rArr sin theta = (4)/(5)`
As sphere is at equilibrium,
`T sin theta = w`
`rArr T ((4)/(5)) =w`
`T = (5w)/(4)`