Physics Equations “Electricity” MCAT
Electricity
F = (k)(q1)(q2) / ( r^2)
**Coulomb’s Law — remember that opposite charges attract each other and like charges repel each other**
Electric Field’s due to a point charge
The electric field that exists at a point in space is the electrostatic force felt by a test charge at the point divided by the charge itself
E = (force) / (test charge)
**if we plug the Coulumbs equations we get E = k(q1)/(r^2)**
**test charge also shown as qo
Constant electrical fields
(force) = (qo)(E)
The electrical potential V at any given point is the electrical potential energy of a test charge qo, divided by the charge itself:
V = (EPE) / (qo)
**EPE (electrical potential energy) = (E)(q)(d)**
**plugging in these two equations we get V = Ed — note that Voltage is the potential for work by an electric field to move any charge from one point to another**
Volatge by a point charge:
V = (k)(q1) / (r)






















