How do you know you are doing work

The necleus of an atom is made up of what subatomic particles?

Most short-period comets do not have randomly oriented orbits because

6–43 a food department is kept at 2128c by a refrigerator in an environment at 308c. the total heat gain to the food department is estimated to be 3300 kj/h and the heat rejection in the condenser is 4800 kj/h. determine the power input to the compressor, in kw and the cop of the refrigerator.