Static Electricity Summary

Static Electricity

Static electricity arises from an imbalance of electric charge (positive or negative) on an object.

Charging Objects

Charging by Friction

Electrons transfer between objects when they are rubbed together.

Charging by Contact

Electrons move between objects upon contact until charge distribution is equal.

Charging by Induction

Charge redistribution occurs in an object due to the proximity of a charged object, without direct contact.

Grounding

Connecting a charged object to the Earth neutralizes it by allowing charge to flow to or from the Earth.

Coulomb's Law

$F = k * (|q1 * q2| / r^2)$

Where:

$F$ is the electrostatic force in Newtons.

$q1$ and $q2$ are the magnitudes of the charges in Coulombs.

$r$ is the distance between the charges.

$k$ is Coulomb's constant ($9 * 10^9 N⋅m^2/C^2$).

Electrostatic forces can be attractive or repulsive, depending on the signs of the charges.

Elementary Charge

The elementary charge ($e$) is $1.6 * 10^{-19}$ Coulombs; protons have a charge of +e, and electrons have a charge of -e.