Question

Two equal, but oppositely charged particles are attracted to each other electrically. The size of the force of attraction is 98.9 N when they are separated by 73.9 cm. What is the magnitude of the charges in microCoulombs ?

Answer 1

Using Coulomb's law:

`F=K\cdot(|q1||q2|)/(r^2)`

Where:

`\begin{gathered} K=8.988*10^9 \\ r=0.739m \\ F=98.9N \\ |q1|=|q2| \end{gathered}`

Therefore:

`98.9=8.988*10^9\cdot(q1^2)/((0.739^2))`

Solve for q1:

`\begin{gathered} q1=\sqrt{((98.9)(0.739^2))/(8.988*10^9)} \\ q1\approx7.75*10^(-5)C \end{gathered}`