Angular Momentum of a Flywheel?

Question

The mass of a flywheel is 5.8 10^4 kg. This particular flywheel has its mass concentrated at the rim of the wheel. If the radius of the wheel is 2.8 m and it is rotating at 358 rpm, what is the magnitude of its angular momentum?

Answer 1

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Answer 2

Angular Momentum (L) = I x Omega

(but I = m r^2 for a hollow object, which in this case it is)

L = m r^2 Omega

First we need the RPM to be converted to Radians per second, therefore....

358 / 60 = 5.9667 revs per second.

5.9667 x 2 pi = 37.4899 radians per second

Now we substitute in....

L = 5.8 x 10^4 x (2.8)^2 x 37.4899
L = 1.704 x 10^7 kg m^2 s^-1

Hope this helps....