SPH 4U, T3L3, Electric Field Energy v2 - Google Sites

Fields: Note 3

Electric Field Energy Electrostatics have a close connection to gravitation. We can compare the potential energy in a gravitational field with the potential energy in an electric field: Gravitational Electrostatic Potential Energy: Potential Energy: *Note: All variables have the same units as Coulomb’s Law. Unit Analysis: It is extremely important that students do not get mixed up with Coulomb’s Law (which describes a FORCE) and electrostatic potential energy (which is a measure of ENERGY). Force and energy are two completely different concepts when examining a system. When we lift a mass off the ground, we give it gravitational potential energy. In a similar way, when we separate two charges, we give them potential energy as well (as described in the equation above). We can use this potential energy in a conservation of energy equation. Note that it is possible for Eg to be positive or negative. Remember that if the energy is positive, this signifies a(n) ___________________ while if the energy is negative, this signifies a(n) ____________________. Eg. 1. Two protons (q = +1.6x10-19 C) are at rest and separated by a distance of 10.0 nm. When one proton is released, what velocity will it be travelling at after it has moved a distance of 10.0 cm from the other proton?