Hey, I did a lab yesterday, and I am working on the report right now, my problem is my teacher confused the hell out of me with what it is I need to have in the report. the experiment was this: We took a car and placed it on a track with a photo strip at the top, and sent it through a photo gate, this gave us the instantaneous velocity. Then we had to set it up so that the car went through two photo gates from 180cm until 10 cm, reducing the distance by 10cm each time. So basically I have a value for what the instantaneous velocity should be from part A of the lab. From part B, I have a chart of 18 different runs, which gives change in time, distance and all that good stuff, and a graph of Velocity/Time. I did this in excel. What I need to find is the instantaneous velocity of the graph i think? I think that means I need to find the limit as t goes to 0 of my data, anyone know how to do that, or can point me in the right direction?