Electric potential and electric potential energy - Electrostatics
Electric potential and electric potential energy
Lessons
Notes:
In this lesson, we will learn:
- The meaning of electric potential and electric potential energy
- How to understand electric potential energy problems by analogy to gravitation problems
Notes:
- Electric potential energy (Ep) is the energy stored in a charge due to its location in an electric field. For example, moving two like charges close together stores potential energy, since the charges repel each other. Separating opposite charges also stores potential energy, since the charges attract each other. It is similar idea to gravitational potential energy.
- It is useful to calculate changes in electric potential energy using the concept of electric potential difference (). An electric potential () is the electric potential energy of a charge q, divided by q. is the difference in between two points.
Electric Potential Energy (Two Point Charges)
electric potential energy, in joules (J)
(Coulomb's constant)
charge on each body, in coulombs (C)
distance between charges, in meters (m)
Electric Potential Energy (Charge in Constant Electric Field)
: electric field, in newtons per coulomb (N/C)
: charge that experiences the , in coulombs (C)
: distance from location chosen as J, meters (m)
Electric Potential
: electric potential, in volts (V)
: electric potential energy, in newtons (N)
: charge that experiences the potential, in coulombs (C)
Electric Potential Difference
: electric potential difference, in volts (V)
: electric potential at initial and final points, in volts (V)
: charge that experiences the potential, in coulombs (C)
: work to move from the initial point to the final point, in joules (J)
: change in potential energy of between the initial and final points, in joules (J)
Useful Constants
(Coulomb's constant)(Elementary charge. )
kg
kg
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1.
Electric potential energy and electric potential between parallel plates (constant E)
There is a constant electric field of 11 500 N/C between a pair of oppositely-charged parallel plates spaced 0.0475 m apart.
