How Do You Calculate Power Input for an Alternator at 3000rpm?

[fran1942]

Homework Statement

An alternator runs at 3000rpm and produces a sinusoidal output voltage with an amplitude of 100V. Calculate the power input required to turn it.

Homework Equations

Ohms Law: I=V/R, R=V/I, V=IR, Watts Law P = VI
Lenz's law regarding back EMF.

The Attempt at a Solution

I know I should be using the above formulas, but I cannot understand how to make the calculation with only the information that was provided. Can someone please help with the calculation.
Thanks kindly for any help.

 

[Jobrag]

You are correct you need more data.