At certain times the demand for electric energy is low and electric energy is used to pump water to a reservoir 45 m above the ground and then used to drive turbines during high demand periods. if this process is 70.0% efficient, how much water must be raised to produce 150 mw of power for 3 hours?

An observer that stands still as the electron moves by him, will observe

For this car, predict the shape of a graph that shows distance (x) versus time (t). note that time is the independent variable and will be on the bottom axis. need asap

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?