What is the effect of bringing like charges closer together?
Increases the electric potential energy of the system (positive $U_E$).
What happens to the electric potential energy if the distance between two opposite charges increases?
The electric potential energy becomes less negative (increases).
What is the effect of charges moving to a lower potential energy configuration?
Stored energy is released (like a book falling).
What is the effect of doubling the distance between two charges?
The potential energy is halved.
What happens when work is done by an external force to move charges into their current arrangement?
The electric potential energy stored in the system increases.
How do you calculate the electric potential energy for a system with multiple charges?
1. Calculate $U_E$ for each pair of charges using the formula $U_{E} = k frac{q_1 q_2}{r}$. 2. Add all the individual potential energies together.
What is the first step to determine the electric potential energy of a system?
Identify all the charges in the system and their positions.
What is the second step to determine the electric potential energy of a system?
Determine the distance between each pair of charges.
What is the third step to determine the electric potential energy of a system?
Calculate the electric potential energy for each pair of charges using the formula $U_{E} = k frac{q_1 q_2}{r}$.
What is the last step to determine the electric potential energy of a system?
Sum the electric potential energies for all pairs to find the total electric potential energy of the system.
Compare and contrast positive and negative electric potential energy.
Positive $U_E$: Like charges, repulsive force. Negative $U_E$: Opposite charges, attractive force.
Compare the electric potential energy between two charges when the distance is 'r' and when the distance is '2r'.
At distance 'r': $U_E = k frac{q_1 q_2}{r}$. At distance '2r': $U_E = k frac{q_1 q_2}{2r}$. Doubling the distance halves the potential energy.
Compare the electric potential energy and electric potential (voltage).
Electric potential energy: Energy per system of charges. Electric potential (voltage): Electric potential energy per unit charge.
Compare the electric potential energy of a two-charge system versus a multi-charge system.
Two-charge system: Direct calculation using $U_{E} = k frac{q_1 q_2}{r}$. Multi-charge system: Superposition principle, summing $U_E$ for all pairs.
Compare scalar and vector quantities.
Scalar: Magnitude only. Vector: Magnitude and direction
