what form of energy do people use?

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also doesnt E=mc squared mean energy=mass times ? squared....
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how does increasing height affect gravitational potential energy?

~i have a HUGE semester final~ 100+ questions...~

Most folks use thermal energy a lot, and electrical energy second.

In the conversion of mass to energy, energy= mass*speedofLight^2

GPE= mass*g*height so increased height means more GPE