Question

How can instantaneous velocity be found from a displacement-time graph?

Answer 1

In a graph of displacement vs. time (that is, a function `x(t)`, where `x` is displacement and `t` is time), assuming the function is continuous and differentiable throughout, instantaneous velocity at any point can be found by taking the derivative of the function with respect to `t` at that point.

A similar question was asked and answered here: http://socratic.org/questions/how-do-you-find-instantaneous-velocity-from-a-position-vs-time-graph? Simply substitute "displacement" for any mentions of "position" or "time."