Two blocks connected to identical ideal springs are oscillating on a horizontal frictionless surface. The motion of the blocks A and B over time are shown in the graph below. Displacement (cm) block A block B ---- 3- Time (s) -1- -2- -3. Why are the periods different for blocks A and B? O Block B has a shorter period because its smaller amplitude means the spring constant is bigger. O Block B has a shorter period because it has less mass. O Block A has a longer period because it has a larger amplitude. O Block B has a longer period because it has more mass