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ss7ja [257]
3 years ago
15

An ideal Carnot refrigerator with a performance coefficient (COP) of 2.1 cools items inside of it to 5.0° C. What is the high te

mperature needed to operate this refrigerator?
A) 7° C
B) 589° C
C) 137° C
D) 16° C
Physics
1 answer:
otez555 [7]3 years ago
5 0

Answer:

the high temperature needed to operate this refrigerator is C) 137.4° C

Explanation:

Hello!

The carnot refrigeration cycle is one in which a machine absorbs heat from an enclosure and expels it to the surroundings, the equation that defines the COP performance coefficient for this cycle is:

COP=\frac{T1}{T2-T1}

COP=performance coefficient =2.1

T1=  Low temperature

T2=high temperature

Now use algebra to find the high temperature

COP=\frac{T1}{T2-T1}\\(T2-T1)=\frac{T1}{COP}\\T2=\frac{T1}{COP}+T1\\T2=T1(\frac{1}{COP} +1)

If we replace the values:

note = remember that the temperature must be in absolute units, for which we must add 273.15 to the low temperature to find the temperature in Kelvin

T1 = 5 + 273.15 = 278.15K

T2=278.15(\frac{1}{2.1} +1)=410.60k

In celsius

T2=410.60-273.15=137.4° C

the high temperature needed to operate this refrigerator is C) 137.4° C

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