2. Planet Alpha Omega has a mass of 2.75 x 1025 kg and a diameter of 20,300 km. Calculate the orbital period AND the velocity for a satellite orbiting the planet at an altitude of 720. km above the surface of the planet.
Orbital period [sec] =
Velocity [m/s] =
3. A satellite is orbiting Earth at an altitude of 1,830 km above Earth's surface. Calculate the orbital period
AND the velocity of the satellite.
Period [sec] =
velocity [m/s] =
4. A rock is tied to the end of a string and spun in a circle. The string is 1.80 m long; the rock spins with a
centripetal acceleration of 9.40 m/s2. Calculate the period of revolution (T) of the rock.

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?