Comparing different substances going through the same change in temperature range, how can we tell

Question

Comparing different substances going through the same change in temperature range, how can we tell

A. Which substance cools off/warms up faster?

B. Which requires more heat?

C. Which expands/contracts more? 

Answer 1

A::The rate of an object cooling or heating will depend on several factors. The rate will depend on the temperature difference of the object and its environment. Obviously ice will melt faster in an oven at 400 degrees. The rate will also be proportional to a constant which will depend on surface area and on the particular material. You would need to consult a reference book for your material. There are three ways that heat is transferred: radiation, conduction and convection. These are radiation, convection and conduction and all will depend on the environment.

B:This is a much simpler question. Each material has a constant which is the specific heat. Heat is energy so you need to know how much heat energy in joules, the specific heat, and the mass of the object. The change in temperature is proportional to the first two and inversely proportional to the mass.

C:Once again this depend on the material. You just need to look up the coefficient of expansion for the material. Water is a strange substance which actually expands as it turns to ice.