A perfect Carnot engine operates between the temperatures of 300K ...

[justinmsk]

A perfect Carnot engine operates between the temperatures of 300K and 700K, drawing 60 kJ of heat from the 700K reservoir in each cycle. How much heat is dumped into the 300K reservoir in each cycle?
 
  A) 38 kJ
  B) 34 kJ
  C) 30 kJ
  D) 26 kJ
  E) 42 kJ

Question 2

One of the most efficient engines built so far has the following characteristics:
 
  combustion chamber temperature = 1900C
   exhaust temperature = 430C
   7.0  109 cal of fuel produces 1.4  1010 J of work in one hour, where 1 cal = 4.19 J
 
  (a) What is the actual efficiency of this engine?
  (b) What is the Carnot efficiency of the engine?
  (c) What is the power output of this engine?

Question 3

A coal-fired plant generates 600 MW of electric power. The plant uses 4.8  106 kg of coal each day. The heat produced by the combustion of coal is 3.3  107 J/kg.
 
  The steam that drives the turbines is at a temperature of 300C, and the exhaust water is at 37C. (a) What is the overall efficiency of the plant for generating electric power? (b) What is the maximum efficiency that this plant could possibly have using the same temperature extremes that it presently uses? (c) How much thermal energy is exhausted each day by this plant?

[Jadwiga9]

Answer to Question 1

wohoo thank youuu.

Answer to Question 2

You just saved me a lot of time.

Answer to Question 3

(a) 33 (b) 46 (c) 1.1  1014 J

[justinmsk]

Excellent

[recede]

Gracias!