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

`I=12.5\ kg.m^2`

Step-by-step explanation:

Given that

Stored energy ,
`E=1* 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=(1)/(2)\omega^2 I`

`I=(2\ttimes E)/(\omega^2)`

Now by putting the values in the above equation we get

`I=(2* 1* 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`