Equipotentials: The Gravitational Analogy
Topo maps have lines of constant gravitational potential (that is, equal height) drawn on
Topographical lines on a map are lines of constant elevation.
As gravitational potential energy is given by
PE = m(gh)
U = qV
These lines of constant height are thus lines of constant gravitational potential.
ΔU elec qΔV
We can also make a gravitational analogy with the electric field.
The downhill force is greatest where the contour lines are closest together, and
the direction of the force is perpendicular to the contours.
The force felt by charges can be described by having the charges immersed inside
E = d
The electric field can refer to the force per unit charge (Newtons per Coulomb), or to a
change in voltage over some change in distance (Volts per Meter).