Coal seams measures 3 ft thick by 12 ft across and 150 ft in length. if the average energy value per pound of this given coal field is 11,000 btus/pound and this coal weighs 12 lbs per cubic foot then what is the energy value

What are similarities and differences between refraction, reflection, diffraction and absorption?

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?

Which composition of water moves to begin a deepwater current?