REPRESENTING CAUSE-EFFECTS: RELATIONSHIPS -COORDINATES, FUNCTIONS & EQUATIONS
  * Representing CAUSE and EFFECT. What is a "function"?                                             WIP
  * Physical, graphic, and symbolic representation of equality (algebra, equations)
  * Playing with equations representing weight balance
  * Construct a linear function (mechanical-2 variables)
  * Construct another linear function (electrical-2 variables)
  * Playing with a line - linear function
  * Viewing a Non-Linear Function Graph (mechanical-2 variables)
  * The free fall quadratic equation - Needs also -EXCEL
  * View a 3-variable coordinate & volume representation graph
  * Play Algebra with a Linear Equation (function)
  * Making mechanical movement from electricity of chemicals in batteries
  * Making electricity by moving magnets over conductor wires

  * Phet Java physics simulations