1. The problem statement, all variables and given/known data Here are the free response questions: https://secure-media.collegeboard.org/digitalServices/pdf/ap/ap15_frq_physics_c-m.pdf Here are the solutions: https://secure-media.collegeboard.org/digitalServices/pdf/ap/ap15_physics_cm_sg.pdf I do not understand how they solved a few of the questions 2. Relevant equations more below 3. The attempt at a solution So for 1. e. Why do they have the difference in slopes of the two line segments with the the first segment being steeper than the second? And why is the point before tf/2 and not at tf/2? In other words.... what is the explanation behind the way they drew the graph the way they did? And then for 3. (c) Why do they choose to have velocity squared for the y-axis and the length for the horizontal axis? I see how the units of the slope of the line match the acceleration... but I do not understand the theory that allows g to be calculated from it. Could anyone please explain? Thanks in advance so much!