The angular momentum of a rotating body changes from `A_(0)` to `4 A_(0)` in 4 min. The torque acting on the body is

Options

A. `(3)/(4)A_(0)`
B. `4A_(0)`
C. `3A_(0)`
D. `(3)/(2)A_(0)`

Answer

A

Explanation

Torque = rate of change of angular momentum
`"or "tau=(dJ)/(dt)`
Given, `" "dJ=4A_(0)-A_(0)=3A_(0), dt="4 min"`
`therefore" "tau=(3)/(4)A_(0)`