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Calculate the kinetic energy (KE) that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path arond the sun is circular. For comparison, the total energy used in the U.S. in one year is about 9.3 X 10^19 J.

I know that the KE of a rigid object is 1/2*(moment of inertia)*(angular vel.)^2 but how to go solve for KE w/o given any of this info?

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# Homework Help: Rotational Work & Energy problem

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