A person pulls a sled along the road 15m by exerting a constant force of 250 N at angle of 27° for 9 minutes. How much work and power output of that person.

He latent heat of vaporization for ethyl alcohol is 854 j/g. the amount of energy, rounded to the nearest whole number, needed to change 5.20 grams of ethyl alcohol from a liquid to a gas is

If you put a helium-filled balloon in the refrigerator, what will happen?

Since the energy was not raising the temperature of the water during these segments, what was the energy used to do instead? your answer must include an explanation of what is happening to the molecules.