Heat, Part 2

Two objects are made of the same material, but have different masses and temperatures. If the objects are brought into thermal contact, which one will have the greater temperature change? The one with the higher initial temp. The one with the lower initial temp. The one with the larger mass. The one with the smaller mass. The one with the higher specific heat. 90

Two different objects receive the same amount of heat Two different objects receive the same amount of heat. Which of the following choices is NOT a reason why the objects may have different temperature changes? They have different initial temps. They have different masses. They have different specific heats. 90

You step out of a swimming pool on a hot day, where the air temperature is 90° F. Where will you feel cooler, in Phoenix or in Philadelphia? Equally cool in both places. Phoenix. Philadelphia. 90

Answers 4, Q=mcDT – They both have the same Q (heat flows from one to the other). If same c, then smaller mass means bigger DT. 1. The initial temp does not affect the CHANGE in temp, Q=mcDT 2. since it’s hot, the water will evaporate from your skin. Evaporation takes energy which comes from your skin (cooling your body). In Phoenix the air is drier and thus can absorb more water making the evaporation process easier and more likely.