Answer:
A) 
B) 
C) 
Explanation:
Given:
- mass of flywheel,

- diameter of flywheel,

- rotational speed of flywheel,

- duration for which the power is off,

- no. of revolutions made during the power is off,

<u>Using equation of motion:</u>



Negative sign denotes deceleration.
A)
Now using the equation:


is the angular velocity of the flywheel when the power comes back.
B)
Here:

Now using the equation:


is the time after which the flywheel stops.
C)
Using the equation of motion:


revolutions are made before stopping.
Answer:
a. 3 s.
Explanation:
Given;
angular acceleration of the wheel, α = 4 rad/s²
time of wheel rotation, t = 4 s
angle of rotation, θ = 80 radians
Apply the kinematic equation below,

Given initial angular velocity, ω₀ = 0
Apply the kinematic equation below;

Therefore, the wheel had been in motion for 3 seconds.
a. 3 s.
Answer:
by applying a magnetic force to recycled materials