AP Physics 2: Algebra-Based Flashcards: Electric Potential Energy
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What is the equation for the electric potential energy ($U_E$) between two point charges, $q_1$ and $q_2$?
The equation is $U_{E}=k\frac{q_{1}q_{2}}{r}$, where r is the distance between the charges and k is Coulomb's constant.
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What is the equation for the electric potential energy ($U_E$) between two point charges, $q_1$ and $q_2$?
The equation is $U_{E}=k\frac{q_{1}q_{2}}{r}$, where r is the distance between the charges and k is Coulomb's constant.
Define the electric potential energy of a system of two point charges.
It is the amount of work required for an external force to bring the point charges from infinitely far away to their current positions.
A system consists of a positive charge and a negative charge. What is the sign of this system's electric potential energy?
The electric potential energy will be negative because the product of the positive and negative charges ($q_1 q_2$) is negative.
How would you begin to calculate the total electric potential energy for a system of three point charges?
You would identify all unique pairs of charges in the system and then calculate the electric potential energy for each pair individually.
How is the total electric potential energy calculated for a system containing more than two charged objects?
The total electric potential energy is the sum of the potential energies of the individual interactions between each pair of charged objects in the system.
If two positive charges are brought together from infinitely far away, will the system's electric potential energy be positive or negative?
The electric potential energy will be positive because the product of the two positive charges ($q_1 q_2$) is positive.
What is the relationship between electric potential energy and the work done by an external force to assemble a charge system?
The electric potential energy of the system is equal to the work done by the external force to bring the charges from infinity to their final positions.
In the equation $U_{E}=k\frac{q_{1}q_{2}}{r}$, what does the term $k$ represent?
The term $k$ is a constant of proportionality, also known as Coulomb's constant, which is equal to $\frac{1}{4\pi\epsilon_{0}}$.
What is the reference point where the electric potential energy of a system of charges is considered to be zero?
The reference point is when the point charges are infinitely far away from each other.
How does the electric potential energy of two point charges change as the distance 'r' between them increases?
As the distance 'r' increases, the magnitude of the electric potential energy decreases, approaching zero as r approaches infinity.