(a) 1200 rad/s
The angular acceleration of the rotor is given by:

where we have
is the angular acceleration (negative since the rotor is slowing down)
is the final angular speed
is the initial angular speed
t = 10.0 s is the time interval
Solving for
, we find the final angular speed after 10.0 s:

(b) 25 s
We can calculate the time needed for the rotor to come to rest, by using again the same formula:

If we re-arrange it for t, we get:

where here we have
is the initial angular speed
is the final angular speed
is the angular acceleration
Solving the equation,

The time constant determines how long it takes for the capacitor to charge.
To find the answer, we have to know more about the time constant of the capacitor.
<h3>What is time constant?</h3>
- The time it takes for a capacitor to discharge 36.8% of its charge in a discharging circuit or charge up to 63.2% of its maximum capacity in a charging circuit, given that it has no initial charge, is the time constant of a resistor-capacitor series combination.
- The circuit's reaction to a step-up (or constant) voltage input is likewise determined by the time constant.
- As a result, the time constant determines the circuit's cutoff frequency.
Thus, we can conclude that, the time constant determines how long it takes for the capacitor to charge.
Learn more about the time constant here:
brainly.com/question/17050299
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