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.
Missing questions: "find the speed of the electron".
Solution:
the magnetic force experienced by a charged particle in a magnetic field is given by

where
q is the particle charge
v its velocity
B the magnitude of the magnetic field

the angle between the directions of v and B.
Re-arranging the formula, we find:

and by substituting the data of the problem (the charge of the electron is

), we find the velocity of the electron:
A trace gas is a gas which makes up less than 1% by volume of the Earth's atmosphere, and it includes all gases except nitrogen (78.1%) and oxygen (20.9%). The most abundant trace gas at 0.934% is argon.