A flywheel is rotating with initial angular velocity about a fixed axis
PHYSICS · Subjective · AP · Physics 1: Algebra-based · Torque and Rotational Dynamics · Torque and Rotational Dynamics
Problem
A flywheel is rotating with initial angular velocity ω0 about a fixed axis. It is first subjected to a constant angular retardation α (where α>0) until it comes to rest. Without any pause, a constant angular acceleration β (where β>0) is then applied in the opposite sense until the flywheel acquires an angular velocity of magnitude ω0 but in the direction opposite to the initial one.
(a) Derive an expression for the time t1 taken by the flywheel to come to rest.
(b) Derive an expression for the additional time t2 required for the flywheel to reach the angular velocity of magnitude ω0 in the opposite sense.
(c) Hence, show that the total time taken for the entire process is
t=t1+t2=αω0+βω0.