A disc of radius 10 cm can rotate about an axis passing through its centre and perpendicular to its plane. A force of 10 N is applied along the tangent in the plane of the disc. If the moment of inertia of the disc about its centre is `5 kg m^(2)`, then the increase in the angular velocity of the disc in 10 s will be

Options

A. 2 rad/s
B. 4 rad/s
C. 1 rad/s
D. 50 rad/s

Answer

A

Explanation

`tau = I alpha`.
`therefore alpha =(tau)/(I)=(rF)/(I)=(0.1xx10)/(5)=0.2`
`therefore omega_(2)=omega_(1)+alpha t=0+0.2xx10=2`