1. The problem statement, all variables and given/known data What is the mechanical advantage of a staircase that is 10 meters long (horizontally) and 5 meters high (vertically)? 2. Relevant equations MA=Length/Height 3. The attempt at a solution MA=2.2 I'm certain that this is the answer my teacher is looking for, but it does not make sense to me. It seems to me that stairs are not always the same as an inclined plane, but that this may depend on the configuration of the steps and how they are climbed. For example, what if the stairs have 2 equally spaced steps (each 2.5, meters high) or 4 equally spaced 1.25 meter high steps. I don't see how those configurations provide any mechanical advantage -- I have to climb each high step and then walk over the flat distance between steps. There is no reduction in the force I have to use to life my body. In the more typical configuration, if I move my body horizontally over the flat part of the steps and vertically at the edge of the steps, how do the stairs provide any mechanical advantage? Again, there is no reduction in the force I have to use to lift my body. Furthermore, even if I were to move my body at a constant slope upward equal to the average slope of the stairs (as if I were a block sliding on a flat inclined plane), isn't it really me that preserves that slope? In other words, couldn't I climb a vertical ladder and essentially zigzag body back and forth as I climb so that my body center of mass is always moving up at any given slope? By my teacher's formula, the ladder has an MA=1. I can only imagine that I'm missing something important here because my teacher said he's been using this same problem set since before I was born. Can someone please help me figure out where my reasoning has gone wrong?