1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ss7ja [257]
4 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]4 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

You might be interested in
A human being can be electrocuted if a current as small as 51.0 ma passes near the heart. an electrician working with sweaty han
boyakko [2]

The fatal current is 51 mA = 0.051 Ampere.

The resistance is 2,050Ω .

Voltage = (current) x (resistance)

            =  (0.051 Ampere) x (2,050 Ω)  =  104.6 volts .

==================

This is what the arithmetic says IF the information in the question
is correct.

I don't know how true this is, and I certainly don't plan to test it,
but I have read that a current as small as  15 mA  through the
heart can be fatal, not  51 mA .

If 15 mA can do it, and the sweaty electrician's resistance is
really 2,050 Ω, then the fatal voltage could be as little as  31 volts !

The voltage at the wall-outlets in your house is  120 volts in the USA !
THAT's why you don't want to stick paper clips or a screwdriver into
outlets, and why you want to cover unused outlets with plastic plugs
if there are babies crawling around.
6 0
3 years ago
Earth has an __ of about 30 percent, reflecting much of the sun's radiation<br> back into space.
kotegsom [21]

Answer: albedo

Explanation: ?

5 0
3 years ago
a student needs to calculate the density of some liquid. the student knows that density is equal to mass divided by volume. Name
Advocard [28]

The student can measure a liquid's volume by using a graduated cylinder, or a beaker. Mass can be measured by first weighing an empty container on a scale, and then by adding the liquid to the container and weighing it again.

7 0
4 years ago
Read 2 more answers
The sound absorber is kept at the wall of cinema hall why ​
Sladkaya [172]

Answer:

because it causes echoes walls are good reflectors of sound

Explanation:

pls mark brainliest ;)

4 0
3 years ago
What physical property of nylon and leather make them get materials to use for shoelaces
Ulleksa [173]

What physical properties of nylon and leather make them good materials to use for shoelaces? A. high density and low conductivity B. durability and flexibility C. hardness and durability D. low viscosity and flexibility.

4 0
3 years ago
Read 2 more answers
Other questions:
  • Select the correct answers.
    12·2 answers
  • Sonic boom from a plane is an example of a shockwave. Give another example where a shockwave is produced
    12·1 answer
  • An inductor with an inductance of 3.00 H and a resistor with a resistance of 14.0 Ω are connected to the terminals of a battery
    6·2 answers
  • A 2.5 kg cat is resting on top of a bookshelf that is 3 meters high. What is the cats gravitational potential energy relative to
    5·1 answer
  • A Rankine oval is formed by combining a source-sink pair, each having a strength of 36 ft2/s and separated by a distance of 15 f
    12·1 answer
  • Why do we say “work done” and “energy change”
    8·1 answer
  • As you bring a prism close to the angle of total internal reflection, what happens to the angle of the refracted beam outside th
    15·1 answer
  • .<br><br>Answer in units of N.
    8·1 answer
  • What is the atomic composition of methane
    14·2 answers
  • La resultante de dos fuerzas perpendiculares es de 25 N. Si una de las fuerzas tiene de intensidad 7 N, ¿cuál es el valor de la
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!