In hydroelectric dams, gravitational potential energy is used to produce electrical energy. what is the mass of water that must fall over a dam that is 12 m high in order to produce the same amount of energy in an aa battery (10,800 j)?

Organelles are 1. responsible for producing power for the cell 2. tiny structures in the cell that carry out the cell's activities 3. responsible for digestion in the cell 4. found outside of the membrane

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?