1. The problem statement, all variables and given/known data From my textbook there is a note that says " A reference datum must always be define in order to obtain the height h. I don't quite understand what is it trying to tell me. I already had define my datum 1 as position 1 and datum 2 as position 2. On my 2nd diagram , I made a red line, is that the Height that I need to find? 3. The attempt at a solution Working for Block position 2 E2=K2+G2+S2 =1/2(10)v^2 + 10(9.81)(-h) + 0 Thanks.