Lecture 1: Mechanical Energy

Question 1

What is heat?

Answer 1

A macroscopic expression of the microscopic motion of atoms and molecules, ‘thermal motion’.
It is given the symbol q (random motion).

Question 2

What is temperature?

Answer 2

A way to compare the thermal or heat energy of two objects. Two objects are at the same temperature if no heat moves back or forth when they are brought together. Average kinetic energy is proportional to temperature.

Question 3

What is work?

Answer 3

Work = force x distance
Work is an ordered transfer of energy (unlike temperature). It is given the symbol w (directed motion).
dw = -PdV

Question 4

What does isothermal mean?

Answer 4

Constant temperature

Question 5

What is the maximum work done by the reversible expansion of a gas?

Answer 5

w = -nRTln (P1/P2)

Question 6

What is the Joule experiment?

Answer 6

An experiment to show that heat and work can be interconverted. When you do work on a gas/liquid/solid, it heats up. If you put in heat, you get out work in the form of expansion.