11. Scientists put a sample of water into a sealed tank. Water can be a solid, liquid, or gas. At first, the water was a liquid. Then, the scientists transferred energy out of the substance, and the water changed phase. What happened to the movement of the water molecules?

After the phase change, the water molecules moved . . .

a
faster and started moving away from each other.

b
faster and started moving around each other.

c
slower and started moving in place.

d
slower and started moving around each other.

Conventional hot-water heaters consist of a tank of water maintained at a fixed temperature. the hot water is to be used when needed. the drawback is that energy is wasted because the tank loses heat when it is not in use, and you can run out of hot water if you use too much. some utility companies are encouraging the use of on-demand water heaters (also known as flash heaters), which consist of heating units to heat the water as you use it. no water tank is involved, so no heat is wasted. a typical household shower flow rate is 2.50 gal/min (9.46 l/min ) with the tap water being heated from 51.0 ˚f (10.6 ˚c) to 120 ˚f (48.9 ˚c) by the on-demand heater.what rate of heat input (either electrical of from gas) is required to operate such a unit, assuming that all the heat goes into the water?