3.1 What is Energy?

Potential & Kinetic

Facts about energy:

  • Energy is most typically measured in Joules.
  • Food energy can be measured in Joules or Calories.
  • Energy can be converted from one form to another.
  • Unlike Force or Velocity, energy is a scalar quantity (no direction).
Units for Energy

Quote from famous physicist (Richard Feynman, 1964

For those who want some proof that physicists are human, the proof is is the idiocy of all the different units which they use for measuring energy.

Energy (in all its various forms), has been measured in calories, btu's, foot-pounds, kilowatt-hours, eV, tons of TNT, tons of oil, tons of coal....etc.    Any of these can be converted to Joules.   In this course, we'll pretty-much stick to Joules when we measure or calculate energy.