In the preceding analysis, what assumption did you make about Q (energy flow from surroundings into the system due to a temperature difference)? Q was negligible because the process lasted only a short time. Q can be ignored because colliding objects never get hot. Q = ΔEthermal

Read these sentences from the text. near the equator, the tropics receive the most rain on a consistent basis. as a result, the fresh water falling into the ocean decrease the salinity of the surface water in that region. [. .] . . as the salt content of sea water increases, so does its density. what can you infer about how rain affects the density of surface water near the equator?

Compare and contrast physical changes with chemical changes.

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j