1. The problem statement, all variables and given/known data A 20.0-kg block is connected to a 30.0-kg block by a string that passes over a light frictionless pulley. The 30.0-kg block is connected to a spring that has negligible mass and a force constant of 250 N/m. The spring is unstretched when the system is as shown in the figure, and the incline is frictionless. The 20.0-kg block is pulled20.0 cm down the incline (so that the 30.0-kg block is 40.0 cm above the floor) and released from rest. Find the speed of each block when the 30.0-kg block is 20.0 cm above the floor (that is, when the spring is unstretched. The problem is on page 62 of the document on the attached website along with the diagram. http://www.santarosa.edu/~lwillia2/40/40ch1011_f14.pdf 2. Relevant equations: Conservation of mechanical energy. Mechanical Energy initial = Mechanical Energy final 3. The attempt at a solution I prove that I attempted to solve the problem by attaching a picture below of my unfinished sheet. So my high school teacher assigned the problem above. I just took the link from a college website because it has the problem with diagram and the explanation. I also have the following photographs from the student solutions manual that the book uses, which are attached below. I understand how conservation of mechanical energy works in this case, but I am struggling with another aspect of the problem. So I am struggling to understand one critical aspect of their explanation.... why does the height of the 20.0 kg block when it is pulled back equal the height of the 30.0 kg block when the spring becomes unstreched? I would have thought that because there is a 40 degree angle that things would have been different.... Could someone please explain? Thanks in advance!