This is a graph which shows time and displacement as function of time. I am told to find the average acceleration for the first ten and sixteen seconds. The answers are : 2.5 and 0.7 cm / s 2 . If the image is not showing below, download the attached image. http://img22.imageshack.us/img22/1050/acceleration.jpg [Broken] I found v(10) and v(0) and divided by ten which does not equal 2.5 cm/s^2 or .7cm/s^2. What i did try was however find v(10) and v(8) and divided by 2(1.6 something), which is much closer to 2.5 cm/s^2. Is there some method I am not using?