Answer:
Explanation:
Given that both charges have the same sign (+a), they will experience a repulsive force due to the like charges. This force will cause them to move away from each other.
The electric potential energy (U) between two point charges can be calculated using the formula:
\[ U = \frac{k \cdot |q_1 \cdot q_2|}{r} \]
where:
- \( k \) is Coulomb's constant (\(8.99 \times 10^9 \, \text{N} \cdot \text{m}^2/\text{C}^2\))
- \( q_1 \) and \( q_2 \) are the magnitudes of the charges
- \( r \) is the distance between the charges
Since both charges are positive, the product \( |q_1 \cdot q_2| \) is positive.
When the charges move away from each other, the distance \( r \) in the denominator increases. Since \( r \) is in the denominator, increasing it will decrease the overall potential energy.
So, the correct answer is:
B: They move away from each other, and their electric potential energy decreases.