1. The problem statement, all variables and given/known data Problem is presented as a nonlinear graph. Y-axis is in meters and ranges from 0.0 to 40.0m in increments of 10m, and the X-axis is in seconds, 0.0-5.0s (increments of 1). Points on graph include (0,10), (1,~19), (2, ~23), (3, ~26), (4, ~26), and (5, ~20). Question: "Estimate the instantaneous velocity of the train at 2.0s." (and again at 4.0s). 2. Relevant equations V(av) = delta(x) / delta(t) V(as delta(t) approaches 0) = delta(x) / delta(t). 3. The attempt at a solution Unsure. I understand the concept behind finding instantaneous velocity in that it's an instant measure of motion and includes a directional component, but damn if I can remember how to do it. The notes from class are a bit too complicated to be of use, and guesstimating the slope of a line tangent to x=2 isn't much help, given this graph. Any thoughts?