In which one of Maxwell's Equations was symmetry most important in suggesting changes to the equation?

The first equation

∫E→⋅dA→=q/ε0.

Explanation:

Which represents completely covering the surface with a large number of tiny patches having areas dA→. We represent these small areas as vectors pointing outwards, because we can then take the dot product with the electric field to select the component of that field pointing perpendicularly outwards (it would count negatively if the field were pointing inwards)—this is the only component of the field that contributes to actual flow across the surface.

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.