# Determine Acceleration from Position vs. Time Graph

1. Dec 17, 2007

### petern

The position vs. time graph is wavy and I assume the only point where there is acceleration is where there is a curve, right? It seems like the acceleration is also 0 at the curve though. Is it even possible?

2. Dec 17, 2007

### MrJingles

For a position as a function of time graph, simply find the derivative at the point which you wish to find the velocity for. Find the second derivative of the function for the acceleration. Perhaps if you uploaded an image of the particular graph in question I could be of more use.

(The acceleration will equal zero at any point where the f(t) graph changes concavity)

3. Dec 17, 2007

### petern

and this:

I don't really understand most of it.

4. Dec 17, 2007

### MrJingles

Your first assertion, that acceleration occurs only at curves is correct. Velocity is only equal to zero when it (the position function) has zero slope (ie, no motion--- straight lines and relative max/mins) and acceleration equals zero when the velocity is constant (velocity is a straight line) and when the position graph switches concavity (inflection point). It is important to note that, though velocity may =0 at some point, acceleration may not (although it can).