Thermodynamics - First Law of Thermodynamics

Question 1

heat

Answer 1

• When you add heat energy to an object, it (usually) causes the temperature to increase, which means the molecules of the object move faster. Since molecules have a mass, when they are in motion they have Kinetic Energy (1/2mv2). So energy added by heat goes (at least partly) into the KE of the molecules. If you add up the KE of all the molecules in the object, that is called the “Internal Energy U.” For a diatomic gas (one whose molecules have two atoms, like N2, H2, O2, etc.)

Question 2

first law of thermodynamics

Answer 2

• the branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy