Melting Ice with a Carnot Engine

[horsegirl09]

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.40×10^−2 kg.
Throughout this problem use L_f = 3.34x10^5 J/kg for the heat of fusion for water.

During this time, how much work W is performed by the engine?

I don't know where to start...any help please?

 

[alphysicist]

Hi horsegirl09,

What is the efficiency of this engine? You are able to find a numerical value here.

Once you have that, how is the efficiency related to the work done?

 

[horsegirl09]

I still don't see how i can get the efficiency without any temperatures or heat values

 

[alphysicist]

You do have the temperatures: one reservoir is boiling water and the other reservoir is a mixture of ice and water. What efficiency does that give?

 

[horsegirl09]

Tc=273 k Th= 373 k
n = 1- (Tc/Th)
n = 1- (273/373)
n = 1-.73
n = .27 or 27%

 

[horsegirl09]

n= 1-Tc/Th = W/Qh
how do i get Qh to get W?

 

[TMM]

You know that the exhaust melts a certain amount of water, so from that you can find the heat lost.

 

[horsegirl09]

thanks i got the answer!