Physics lab help, determining acceleration thru V vs T graph?? the point was to determine the acceleration due to gravity. It was this whole experiment with a ribbon tied to a brass weight. it was put into a machine and youd drop the brass weight and the machine would mark dots on it to show how it feel. each dot represented 1/60, 2/60 seconds etc. I had 28 dots in all. The man in charge said the acceleration was supposed to be 9.8 but I dont know what to do, i graphed and made a table of the displacement and time. (for displacement i measured in cm from origin to the other dots). But how do i find the velocity and graph V vs T. please help! --- each dot is at its own interval, dot 1 is 1/60, dot 2 is 2/60 dot 3 is 3/30 etc. eaach obviously has its own distance from origin. and its a free falling object....please help, i was told but am very confused to cound 6 dots (to graph it only has to be 1/10 intervals) and count distance from dot before and dot after the 6th like A..............B.............C (with A B &C being dots) so distance from A--->C divided by 1/30 was velocty. but i dnt get that. please explain! ive been trying so long and am so confused!