Conservation of electric energy

Read Tipler and Mosca (2004) chapter 23 (Electric potential); Pelcovits and Farkas (2024) chapter 10 (Electrostatic) pp.289–302.

You should be able to describe changes in a system due to a difference in electric potential between two locations.

Conservation of electric energy

When a charged object \(q\) moves between two locations with different electric potentials, the resulting change in the electric potential energy \(\Delta U_E\) of the object-field system is given by the following: \[\begin{equation} \Delta U_E = q \Delta V. \end{equation}\]

The movement of a charged object between two points with different electric potentials results in a change in kinetic energy of the object consistent with the conservation of energy.

Review: Conservation of energy

The law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over timesee https://en.wikipedia.org/wiki/Conservation_of_energy

.

The kinetic energysee https://en.wikipedia.org/wiki/Kinetic_energy

of an object translating at velocity \(v\) is given by: \[\begin{equation} KE = \frac{1}{2} m v^2. \end{equation}\]

The (change in) gravitational potential energysee https://en.wikipedia.org/wiki/Gravitational_energy

of an object as it is raised a height \(h\), approximately for objects near the surface of the earth, is given by: \[\begin{equation} \Delta GPE = mgh. \end{equation}\]

If the object is not near the surface of the earth, or motion is large so that the change in distance is significant, this equation does not apply.

See also

References

Pelcovits, Robert A, and Joshua Farkas. 2024. Barron’s AP Physics c Premium. Kaplan North America.
Tipler, Paul A, and Gene Mosca. 2004. Physics for Scientists and Engineers. 5th ed. W H Freeman; Company.