A cylinder of length `20 cm` and radius `10 cm` is rotating about its central axis at an angular speed of `100 rad//s`. What tangential force will stop the cylinder at a unifrom rate is `10 s` ? Given moment of inertia of the cylinder about its axis of rotation is `8.0 kg m^(2)`.

Explanation

Here, `l= 20 cm, r = 10 cm, omega_(1) = 100 rad//s`,
`F = ?, omega_(2) =0, t = 10 s, I = 0.8 kg m^(2)`
`tau = F xx r = I alpha = (I(omega_(2) - omega_(1)))/(t)`
`:. F = (I (omega_(2) - omega_(1)))/(t xx r) = (0.8 (0 - 100))/(10 xx 10//100) = - 80 N`