Why is it impossible for hikers camping near the top of a 14000 foot peak to get a really hot cup if coffee

The boiling temperature is lower at that height due to the lower pressure, and thus, the coffee will boil and evaporate before it gets "really hot".

Explanation:

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.