Question

A charge Q is in position. Another charge q is brought near charge Q and released from rest. Which of the following graphs is the correct representation of the acceleration of the charge q as a function of its distance r from charge Q?

Answer 1

Correct option is : (A)

We use Coulomb’s Law and Newton’s Second Law to determine the acceleration of charge q.

• The force on q due to Q is

\(F = \frac{kQq}{r^2}\)

• Acceleration is given by: 

\(a= \frac{kQq}{mr^2}\) 

This means that acceleration varies inversely with \(r^2\). The correct graph should show a decreasing function of r with a sharp drop.