FYKOS Year 38 Series 1 Problem 4 — falling lens · FYKOS 38 #38.1.4
Physics · optics
Problem
We are holding an object in one hand at a distance D from the ceiling. Where on the vertical axis passing through the object do we have to place a contact lens with a focal length f, so that a focused image is created on the ceiling?
Now, we will place the lens at this distance. The object accidentally falls out of our hand, i.e., it is in free fall. How do we need to move the lens so that the image remains focused? Will the position of the lens approach some specific value after a very long time? Assume that the height of the room is much greater than both D and f.