Why does one side of the Moon’s surface always remain much colder than the other side? A) The colder side of the Moon has a cloud cover over it.
B) The colder side of the Moon is entirely covered with ice.
C) The colder side of the Moon always faces away from the Sun.
D) The colder side of the Moon has many high-altitude mountains.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

Which of these metals are magnetic?

If you held a stone over the mouth of a well and then let it go , what would happen to the stone? explain your answer.