**1. The problem statement, all variables and given/known data**

I got a graph with time on the x-axis, and distance on the y-axis. (see attached picture)

I have to calculate the acceleration using only the distance – time graph.

**2. Relevant equations**

I used S(t)=S(0) + V(0) * t + .5 * a * t^{2}

**3. The attempt at a solution**

That gives 1.30=0+0*3.09 + .5 * a * 3.09^{2}

1.30/(.5/9.5481)=a

a=0.272 m/s_{2}

But I know the acceleration is 0.42171 m/s^{2}, because that’s the slope of the V,t graph. What am I doing wrong here?

Thanks.

http://ift.tt/1m3tGtC