Wolfram|Alpha has energy and power calculators. Solve problems related to energy efficiency, energy to launch, gravitational potential energy, kinetic or relativistic kinetic energy, kinetic energy or relativistic kinetic energy of a sphere, mechanical power, the minimum power required to move an object, kinetic energy of a rotating object, kinetic energy of a point mass rotating about an axis, power exerted on a rotating object, total mechanical energy, gravitational binding energy of a uniform sphere and work.
