In this task you're given a question and you have to paraphrase the question to create the output question while retaining the meaning of the original question.
Q: What's the minimum amount of sensors you need to echo-locate a point in 3D? Each sensor receives the sound at a specific-time, how to locate the point?
A:
A point charge q is located at a distance l from the infinitely conducting plane. What amount work has to be performed in order to slowly remove this charge very far from the plane?