Originally Posted by

**Philippe Lemay**
Does anyone know the equation that can give us for instance... Z energy for a mass of X kilograms, spinning at Y RPMs? I'd really like to find out how fast a small mass has to spin before it can power a weapon's grade laser...

Here is the rotational kinetic energy equation. [Power is simply the rate of energy that is added to or taken away from the rotating object with respect to time.]

The equation requires knowing the moment of inertia, which may be found here (for simple forms).

Last edited by George; 2009-Sep-23 at 04:20 PM.
Reason: corrected power def.

We know time flies, we just can't see its wings.