Electric potential and electric potential energy
0/4
Examples
Lessons
- 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.- Find the amount of work needed to move a proton from the surface of the negative plate to the surface of the positive plate, and how much electric potential energy the proton has gained after it is moved.
- If a proton is held at the positive plate surface and released, find the speed of the proton when it reaches the surface of the negative plate.
- Find the electric potential difference between the two plates. What potential energy would a 6.00×10−7C charge have at the positive plate surface?
- Electric potential energy and electric potential of a point charge (non-constant E)
Find the electric potential at each point A and B, and the potential difference between A and B. If 0.060 J of work must be done on a charge to move it from A to B, find the magnitude and polarity of the charge.
Free to Join!
StudyPug is a learning help platform covering math and science from grade 4 all the way to second year university. Our video tutorials, unlimited practice problems, and step-by-step explanations provide you or your child with all the help you need to master concepts. On top of that, it's fun — with achievements, customizable avatars, and awards to keep you motivated.
Easily See Your Progress
We track the progress you've made on a topic so you know what you've done. From the course view you can easily see what topics have what and the progress you've made on them. Fill the rings to completely master that section or mouse over the icon to see more details.Make Use of Our Learning Aids
Earn Achievements as You Learn
Make the most of your time as you use StudyPug to help you achieve your goals. Earn fun little badges the more you watch, practice, and use our service.Create and Customize Your Avatar
Play with our fun little avatar builder to create and customize your own avatar on StudyPug. Choose your face, eye colour, hair colour and style, and background. Unlock more options the more you use StudyPug.
Topic Notes
In this lesson, we will learn:
Ep: electric potential energy, in joules (J)
k=9.00×109N⋅m2/C2 (Coulomb's constant)
Q1,Q2: charge on each body, in coulombs (C)
r: distance between charges, in meters (m)
E: electric field, in newtons per coulomb (N/C)
q: charge that experiences the E, in coulombs (C)
d: distance from location chosen as Ep=0 J, meters (m)
V: electric potential, in volts (V)
Ep: electric potential energy, in newtons (N)
q: charge that experiences the potential, in coulombs (C)
ΔV: electric potential difference, in volts (V)
Vi,Vf: electric potential at initial and final points, in volts (V)
q: charge that experiences the potential, in coulombs (C)
Wonq: work to move q from the initial point to the final point, in joules (J)
ΔEq: change in potential energy of q between the initial and final points, in joules (J)
e=1.60×10−19C (Elementary charge. qproton=e,qelectron=−e)
mproton=1.67×10−27 kg
melectron=9.11×10−31 kg
- The meaning of electric potential and electric potential energy
- How to understand electric potential energy problems by analogy to gravitation problems
- 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 (ΔV). An electric potential (V) is the electric potential energy of a charge q, divided by q. ΔV is the difference in V between two points.
Electric Potential Energy (Two Point Charges)
Ep=kr2Q1Q2Ep: electric potential energy, in joules (J)
k=9.00×109N⋅m2/C2 (Coulomb's constant)
Q1,Q2: charge on each body, in coulombs (C)
r: distance between charges, in meters (m)
Electric Potential Energy (Charge in Constant Electric Field)
Ep=qEdE: electric field, in newtons per coulomb (N/C)
q: charge that experiences the E, in coulombs (C)
d: distance from location chosen as Ep=0 J, meters (m)
Electric Potential
V=qEpV: electric potential, in volts (V)
Ep: electric potential energy, in newtons (N)
q: charge that experiences the potential, in coulombs (C)
Electric Potential Difference
ΔV=Vf−Vi=qWonq=qΔEqΔV: electric potential difference, in volts (V)
Vi,Vf: electric potential at initial and final points, in volts (V)
q: charge that experiences the potential, in coulombs (C)
Wonq: work to move q from the initial point to the final point, in joules (J)
ΔEq: change in potential energy of q between the initial and final points, in joules (J)
Useful Constants
k=9.00×109N⋅m2/C2 (Coulomb's constant)e=1.60×10−19C (Elementary charge. qproton=e,qelectron=−e)
mproton=1.67×10−27 kg
melectron=9.11×10−31 kg
2
videos
remaining today
remaining today
5
practice questions
remaining today
remaining today