Three charges of 2 mC, -4 mC and -4mC are placed on the vertices of an equilateral triangle of side 10 cm. A charge q is kept on the midpoint between both -4mC charge. Calculate the value of q such that the 2 mC charge remains at equilibrium.

Explanation

To solve the problem, we need to find the value of charge \( q \) that will keep the charge of \( 2 \, \text{mC} \) at equilibrium in the presence of two \( -4 \, \text{mC} \) charges placed at the vertices of an equilateral triangle.

### Step-by-Step Solution:

1. **Understanding the Configuration**:
- We have three charges: \( A = 2 \, \text{mC} \), \( B = -4 \, \text{mC} \), and \( C = -4 \, \text{mC} \) placed at the vertices of an equilateral triangle with a side length of \( 10 \, \text{cm} \).
- The charge \( q \) is placed at the midpoint between charges \( B \) and \( C \).

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