A hollow sphere of mass m and radius 'r' is rotating with velocity `omega`. It suddenly stops and 75% of K.E. is converted into heat. If its specific heat is 's' J/kg/K, the rise of temperature is :

Options

A. `(R^(2)omega^(2))/(4s)`
B. `(3R^(2)omega^(2))/(20s)`
C. `(R^(2)omega^(2))/(12s)`
D. `(2R^(2)omega^(2))/(3s)`

Answer

A

Explanation

Here K.E. = Heat developed
`(75)/(100)xx(1)/(2)xx(2)/(3)mR^(2)omega^(2)=msthetaortheta=(R^(2)omega^(2))/(4s)`