How fast would sound wave travel than the other if a signal was sent through air and water by a distress ship at sea 1 mile from a light house when temperature is 20 °c. p(sound in air at 0°c is 331 m/s and for every at in temperature of air the speed increases by 0.6 m/s. sound waves in under water travel 3 times faster than air.

What does si stand for,when referring to a system of measurement

Which form of pure carbon is so hard that it can be used in cutting tools?

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?