A uniform, 1.0 m radius, 50.0 kg circular wheel (ICM=M R2) spinning at 120 rev/min is subjected to a variable frictional force F(t) = 20.0[1 - (t/ λ )2] (in Newtons) applied tangentially at its rim. If the wheel has to stop rotating exactly at the moment the force becomes zero, the value of λ must be

A uniform, 1.0 m radius, 50.0 kg circular wheel (ICM=M R2) spinning at 120 rev/min is subjected to a variable frictional force F(t) = 20.0[1 - (t/ λ )2] (in Newtons) applied tangentially at its rim. If the wheel has to stop rotating exactly at the moment the force becomes zero, the value of λ must be