Modeling with the Three Basic Elements: Temperature, Torque and Pressure are examples of "Across ariable" or "Efor Angular velocity, Volume Flow Rate and Current are examples of "Through Variable" or "Flow" T F The product of "flow" and "effort" has units of power for all systems Generalized Resistance, Capacitance and Inertia, relate their Effort and Flow, time derivative of effort to flow, time derivative of flow to effort by a proportionality constant, respectively. 1 dF A mechanical Spring is a generalized capacitance with equation-kat' k = spring constant, F-force across the spring and u - difference of velocities of spring ends