What are the Thermodynamic Considerations for an Air Conditioner Cooling a Room?

[theown1]

Homework Statement

An air conditioner operates on 800W of power and has a performance coefficient of 2.80 with a room temperature of 21^oC, and an outside temperature of 35^oC.
a) Calculate the rate of heat removal for this unit.
b) calculate the rate at which heat is discharged to the outside air.
c) calculate the total entropy change in the room if the air conditioner runs for 1 hour. Calculate the total entropy change in the outside air for the same time period.
d) What is the net change in entropy for the system(room+outside air)?

Homework Equations

$$\Delta$$Q=cm$$\Delta$$T
I think that that is the equation of heat lost
Coefficient of performance = Q_{cold, input}/W_input
C.o.P=Q_cold,input/(Q_hot,output-Q_cold,input)

The Attempt at a Solution

a) I'm not sure how to find the rate of heat which is removed

b) I'm not sure either

c) I know that Entropy=Q/T, and
$$\Delta$$S=mcln(T_h/T_c)
c is the specific heat, m is mass

but I'm not sure how to find the final temperature from what's given in the problem, or the mass...


d) once I know the answer to part C, its fairly self explanatory

Can someone guide in the right direction for solving this

 

[rock.freak667]

Using COP=Qc/W to get Qc will give you how much heat is removed from the space.

for part b) you just need to do a simple heat balance on the system. (Consider what quantities are going in and what are going out)