A transmitter of power P sits atop a radio tower broadcasting inall directions. A man standing on the ground a radial distance raway from the transmitter measures the intensity of the radio wavesto be
A) P/(4Ï€r2)
B) P/(Ï€r2)

C) P/(2Ï€r)

D) P/(r2)

What happens when you put a small ice cube in a thermallyisolated container (like a Thermos) containing considerably greatervolume of hot coffee?
A) Heat flows from the ice into the hot coffee. Both ice and coffeeevaporate into a warm, brown fog at an equilibrium temperature thatis the average of the original ice and coffee temperatures.
B) Heat flows from the hot coffee into the ice. The equilibriumtemperature drops to 0 ÌŠC and you end up with iced coffee.
C) Heat flows from the ice into the hot coffee. The ice gets colderand the coffee begins to boil.
D) Heat flows from the hot coffee into the ice, melting the ice andwarming the resulting water up to the equilibrium temperature,which is close to the hot coffee’s original temperature.

An isolated sample of an ideal gas has an initial volume V0. Itscontainer slowly changes shape until only half the volume V0/2remains with no change in temperature. What happens to pressure ofthe gas in the sample?
A) It becomes only half as great.

B) It does not change.
C) It becomes 2 times as great.

D) It becomes 4 as great.