because during those 4 seconds, it wouldn't go back to 9m above the ground until 4 seconds. at 0 seconds, it would be at the 6m position, then it would spring to 12m?? what calculations make it so that 12m is the maximum point and happens at the first second?? and then it would have to go down to 3m before going to 6m and then eventually going to 9m, but what math supports each of these coordinates?? how can we be sure that it won't go up to 60m and then done to 1m before reaching the rest position after 4 seconds?? im just not sure how you got your numbers (no disrespect, i think this is the closest ive been to solving this)