Hello guys. I have issues understanding a rather simple physics concept and I hope you can help me out. I've tried asking help from several people, but nobody was able to isolate the problem. For constant acceleration, it is said that d=(Vi+Vf)/2*t. d being distance, Vi is initial velocity, Vf is final velocity and t is time of the travel. The problem occurs when I try to add - what seems intuitively for me atleast - the distance of object traveled each second with the added velocity from the constant acceleration. An example, object starts at 10m/s and after 10 seconds reach a velocity of 20m/s. 150 = (10+20)/2*10, and (20-10)/10 = 1, so acceleration is 1m/s/s. Now when I try to add the distance traveled of each second over a duration of 10 seconds, I get 10+11+12+13+14+15+16+17+18+19 = 145. I don't add 20 because to my understanding the object doesn't actually travel any seconds with 20m/s, it merely reaches that velocity after going a full second at 19m/s. So I can't the results to match eachother, only if I do something like (10+19)/2*10.