Mechanical Universe

In a world of electric charges and currents, field, forces and voltages, what really matters? When is electricity dangerous or benign, spectacular or useful? The electric potential and its gradient; the potentials of atoms and metals; electric energy, and why sparks jump.

Learning Objectives

Know the definition of a gradient.
Be able to state the graphical relationship between electric field lines and equipotentials.
Be able to state the approximate magnitudes of voltages and forces in matter.
Know the explanation of how a lightening rod works.
Be able to give the definition of the electron volt energy unit and the conversion between it and the joule.
Be able to explain why sparks jump.