An object with a mass of 70 kilograms is supported at a height of 8 meters above the ground, what's the potential energy of the object with respect to the ground?

Find the volume of the ellipsoid x^2+y^2+5z^2=36.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?