The problem is to determine the length (el) of the beam, given that it is perfectly horizontal at the left (slope y'(0) = 0 and y(0) = 0 too) and lifted a given amount (h) at the right: y(el) = h.

Simple beam lying on ground with 0 slope and lifted at the other end.
The problem is to determine the length (el) of the beam, given that it is perfectly horizontal at the left (slope y'(0) = 0 and y(0) = 0 too) and lifted a given amount (h) at the right: y(el) = h.