For flywheel, the formula I ω² /2 shows 

Explanation:

Flywheel:

• A flywheel is used to control the speed variation caused by the fluctuations of energy during each cycle of operation in an engine.
• It acts as a reservoir of energy that stores energy during the period when the supply of energy is more than the requirement and releases energy during the period when the supply of energy is less than the requirements.
• During the power stroke, speed of the engine tends to increase and since the flywheel of heavy mass is connected to the engine its speed also increases.

Variation of turning moment in a four-stroke engine.

The flywheel controls the cyclic fluctuation of speed by gaining energy during the power stroke and releasing the energy during the remaining stroke.

Let, ω = angular speeds, I = Moment pf inertia of the flywheel, E = Kinetic energy of the flywheel.

Then the kinetic energy of the flywheel corresponding to mean angular velocity is given by,

​​\(E~=(\frac{1}{2}\times I\times \omega ^2)\)

• The flywheel does not maintain a constant speed, it simply reduces the fluctuation of speed.
• It does not control the speed variations caused by the varying load.
• Governor regulates the mean speed of an engine when there are variations in the load.