Investigating Particle's Acceleration from Position-Time Graph

[lauriecherie]

Homework Statement

The figure below depicts the motion of a particle moving along an x-axis with a constant acceleration. What are the magnitude and direction of the particle's acceleration?

Can anyone explain to me where to begin on this one? It's a graph of position of time. It's concave up going through points (0,-2), (1,0), and (2,6).

The answer should be in m/s^2. It also let's me choose between -x, +x, -y, and +y for direction.

Homework Equations

The Attempt at a Solution

We didn't do any examples of this in class. I'm not sure where to begin on this one. Of course I don't expect an exact answer, but can someone walk me through it with an explanation. I know x(t)'= v(t) and x(t)"= v(t)'= a(t).

 

[Nabeshin]

One thing you could try is to fit a curve to these three data points and then use the differentiation formulas you wrote down to find the acceleration of the particle.