A hoop ( r = 0.35 m; m = 4 kg) is currently rotating at a constant angular velocity of + 4 rad/s as shown in the image. The forces shown are applied for 3.5s .

In the circuit, the switch s has been open for a long time and r = 125 kohm. it is then suddenly closed. (a) determine the time constant before the switch is closed. s (b) determine the time constant after the switch is closed. _ s (c) let the switch be closed at t = 0. find the current in the switch as a function of time. (use t for time. express your answer in milliamps and seconds.) i(t) =_