A system loses 300 calories of heat and has 800 joules of work done on it.  In joules, find DU.
 
 

A machine operates between 300C and what Celsius temp if its maximum possible efficiency is .25?
 
 

An engine takes in 80J at 100C and exhausts 40J at what Celsius temp?
 
 

My fridge has a c.p. of 12.  If the kitchen is 28C, how cold can it get food?
 
 
 

By cleaning your room, you decrease its entropy.  However, the overall entropy of the system goes up.  Why?
 
 
 

How much work does a machine does 1000J of work when it goes from .3m3 to .9m3 under how many Pa of oressure?
 
 

What is the "heat death" of the universe?  (what will have happened by then?)