A light rope is wound around a hollow cylinder of mass 4kg and radius 40cm. If the rope is pulled with a force of 40N, its angular acceleration is

Options

A. `0.40 rads^(-2)`
B. `0.25 rads^(-2)`
C. `25 rads^(-2)`
D. `40 rads^(-2)`

Answer

C

Explanation

Torque, `tau = I alpha`
`F xx r = Mr^(2) alpha`
`40 xx 0.4 = 4 xx (0.4)^(2) alpha`
`16= 0.64 alpha`
`alpha = (16)/(0.64)`
`= (16)/(64) xx 100`
`=25 rad//s^(2)`