To tackle this problem, we will use the concept of rotational kinetic energy. After determining this energy, we will find the time based on the power definition, which indicates how energy changes over time. Let's begin with the formula for the kinetic energy of a rotating flywheel:

Where
I = moment of inertia
Angular velocity
In this scenario, we have:


Substituting the moment of inertia values for this object yields:



The average power expression is given by:




Hence, the correct conclusion is 620 seconds.
Complete Question
The entire question is displayed in the first uploaded image
Answer:
The right choice is option 3
Explanation:
The question informs us that
The diameter of solenoid 1 is 
The length of solenoid 1 is 
The number of turns of solenoid is 
The diameter of solenoid 2 is 
The length of solenoid 2 is 
The number of turns of solenoid 2 is 
Typically, the magnetic field in a solenoid can be expressed mathematically as

According to this formula we find that


Here C denotes constant
=> 
=> 
=> 
=> 
=> 
=> 
In a series circuit...
-- The overall resistance equals the sum of the individual resistances.
-- The current remains identical throughout the circuit.
The total resistance in this circuit is (3Ω + 6Ω ) = 9Ω
<pThe current at every point measures (V/R) = (12v / 9Ω ) =
1.33 A.
Select choice (a).
Answer:
20.353125 V
Explanation:
m = Mass of proton = 
q = Charge of proton = 
= Velocity of proton at point A = 50 km/s
= Velocity of proton at point B = 80 km/s
The relationship derived from energy conservation is as follows:

The determined potential difference is 20.353125 V