Problem 7 (15 points): Two blocks hang from each end of a massless rope that passes over a frictionless pulley, which hangs by its axle from a spring scale. as shown in the diagram. The pulley is a uniform solid disk. and it has the same mass as all four of the blocks. In this static conguration. the scale reads 75 N. One of the bottom blocks becomes detached from the block above it and falls off, unbalancing the pulley. Find the new reading on the spring scale. Assume the rope does not slide across the surface of the pulley