What is the angular momentum of a gyroscope that is a solid cylinder with a radius of .24 m, a mass of 15 kg and a angular velocity of 140 rad/sec?
The moment of inertia
Substitute into the equation
Crunch in the numbers and you should get
The formula for moment of inertia can be derived by exploiting the definition of moment of inertia,
Hope this helps. I would be happy to explain more on the derivation if you want. Cheers.