When you measure the temperature of an object you are measuring

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?

It is really hard for me right know

(a) if the pressure in gas is doubled while its volume is held constant, by what factor do (i) vrms and (ii) change? (b) is it possible to boil water at room temperature (20oc) without heating it? explain.