An ideal reversible refrigerator keeps its inside compartment at 6°C. What is the high temperature, Th, needed to give this refrigerator a coefficient of performance of 2.7? An ideal reversible refrigerator keeps its inside compartment at 6°C. What is the high temperature, Th, needed to give this refrigerator a coefficient of performance of 2.7? a. 109°C b. 8°C c. 759°C d. 22°C

a. 109°C

Explanation:

The COP (coefficient of performance) of heating pump and refrigerator is the ratio of the output energy and input energy. These coefficients in terms of temperature is given as follows.

The COP of the heat pump =

The COP of the refrigerator =

where Th and Tc are the hot and cold absolute temperatures.

Let's first convert Tc into kelvin.

Tc = 6°C = 6+273 = 279 K

2.7(Th -279) = 279

2.7Th-753.3 = 279

2.7Th = 1032.3

Th = 382.33 K

Th = 382.33 - 273

Th = 109°C

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

answer///terminator or twilight zone;