Final answer:
The distance between the two charges is 28.0 cm.
Step-by-step explanation:
To find the distance between the two charges, we need to calculate the distance between their positions on the x-axis. The position of the -3.0 nC charge is x = -9.0 cm and the position of the 4.0 nC charge is x = 19 cm. We can find the distance by subtracting the position of the first charge from the position of the second charge:
Distance = (19 cm) - (-9.0 cm)
Distance = 28.0 cm
Therefore, the correct answer is option 2) 28.0 cm.