Modeling Algorithm Draw a picture Schematic Sufficient detail to capture important features Label directions of motion

Modeling Algorithm Draw appropriate free body diagrams One for each independent body or degree of freedom Draw and label all forces (guess at a direction of action) Label direction of motion

Modeling Algorithm Write constitutive equations For each force in free body diagrams With appropriate directions Action and re-action forces in opposite directions

Modeling Algorithm Write conservation equations Momentum Energy Mass Volume Charge Concentration etc

Modeling Algorithm Rearrange conservation equations Use substitutions from constitutive relations Monic form So as to see: patterns relationships influences