If a disc starting from rest acquires an angular velocity of `240 "rev min"^(-1)` in 10 s, then its angularw acceleration will be

Options

A. `1.52 rads^(-1)`
B. `3.11 rads^(-1)`
C. `2.51 rads^(-1)`
D. `1.13 rads^(-1)`

Answer

C

Explanation

Here, `omega_(2)=2pi n_(2)=3xx(240)/(60)and omega_(1)=2pin_(1)=0`
The angular acceleration, `alpha=(omega_(2)-omega_(1))/(t)`
`:. alpha=(2pi((240)/(60)-0))/(10)=2.51 "rads"^(-1)`.