Standing on a cliff, I take one rock and throw it straight up at a speed of 30 m/s. I take another rock and throw it at 30 m/s straight down. Suppose the cliff is 50 m high. (Rocks again so that air resistance is negligible.) 30m/s a) Start with just everyday reasoning - no calculations - which rock would be moving faster when it hits the ground, 50 meters below? b) Now find an answer based on the kinematics of constant acceleration-go ahead and calculate, use math, however makes sense to you. Find h(t) and v(t) for each of the rocks, and find their respective speeds when they hit the ground 50 m below the point of release. c) Did your answer to b agree with your answer to a? If not, try to reconcile the contradiction: Figure out what it is about the reasoning in part a or part b that doesn't work. 30m/s 50 m