Question

A rotating flywheel can be used as a method to store energy. If it is required that such a device be able to store up to a maximum of 1.00 ×106J when rotating at 400 rad/s, what moment of inertia is required? a. 50 kg⋅m2b. 25 kg⋅m2c. 12.5 kg⋅m2d. 6.3 kg⋅m2

Answer 1

Answer:

$I=12.5\ kg.m^2$

Explanation:

Given that

Stored energy ,$E=1\times 10^6$

Angular speed ,$\omega =400\ rad/s$

Lets take moment of inertia of the flywheel = I

As we know that stored energy in the flywheel is given as

$E=\dfrac{1}{2}\omega^2 I$

$I=\dfrac{2\ttimes E}{\omega^2}$

Now by putting the values in the above equation we get

$I=\dfrac{2\times 1\times 10^6}{400^2}\ kg.m^2$

$I=12.5\ kg.m^2$

Therefore the moment of inertia of the flywheel will be $I=12.5\ kg.m^2$

The answer will be C.

$I=12.5\ kg.m^2$