The force that every mass exerts on every other mass is called

a) gravity

b) pull

c) matter

d) weight

Gam radio signals can usually be heard behind a hill, but fm often cannot. that is, am signals bend more than fm. explain. (radio signals, as we shall see, are carried by electromagnetic waves whose wavelength for am is typically 200 to 600 m and for fm about 3 m.)

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?

Sodium chloride, nacl, is formed when a sodium atom transfers its electron to a chlorine atom. the difference in charge between the two atoms creates a(n) attraction that bonds them together.