Question

Your mailbox is 4 ft from a straight street. You pace between the mailbox and the street, such that the distance between you and the mailbox is the same as the distance between you and the street. What equation of a conic section describes your path?

Answer 1

You are moving in the path of a parabola.

The conic section  is parabolic - the street is the directrix  and the mailbox is the focus.