Which phenomenon causes the star to appear this way? O redshift
gravitational lensing
O principle of equivalence
O gravitational time dilation

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius

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?

You pump 25.0l of air at atmospheric pressure into a soccer ball that has a volume of 4.50l. what is the pressure inside the soccer ball if the temperature does not change?