A string is wrapped around the rim of a wheel of moment of inertia 0.20 `kg-m^2` nd radius 20 cm. The wheel is free to rotate about it axis. Initially, thewheel is t rest. The string is now pulled by a force of 20 N. Find the angular velocity of the wheel after 5.0 seconds.

Explanation

The torque acting on the wheel is
`tau = Fr = (20 N) (0.20 m) = 4.0 N-m `
The angular acceleration produced is
`alpha = tau/I = (4.0 N-m)/(0.20 kg - m^(2)) = 20 "rad/s"^(2)`
The angular velocity after 5.0 seconds is
` omega = omega_(0)+alphat = 0 + (20 "rad/s"^(2))`
`(5.0 s) = 100 "rad/s"`