X-ray photons of wavelength 0.02480 nm are incident on a target and the Compton scattered photons are observed at 90 degrees.

(a) What is the wavelength of the scattered photon ?

(b) What is the momentum of the incident photon ?

(c) What is the kinetic energy of the scattered electron ?

(d) What is the momentum (magnitude and direction) of the scattered electron ?

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?