Finding acceleration given position and time

[agargento]

Homework Statement

An object is moving in a straight line with a constant acceleration. Its position is measured at three different times, as shown in the table below.
Time (s) | Position, (m)
48.40 | 9.100
49.80 | 17.479
51.20 | 32.816
Calculate the magnitude of the acceleration at t=49.80 s.

Homework Equations

V(t) = V=at
r(t)=r+v₀t+0.5at²
a=ΔV / Δt

The Attempt at a Solution

I started making a 3 equations system, but this got way more complex than I think it should, and way more complicated than we did in class... Is this even the right direction at solving this?

EDIT: sorry for the hassle, solved the question.

 

[gneill]

Would you care to share your method and result?

 

[Cutter Ketch]

Yes you can do it this way. There is another way to think about it, but it isn't really easier.

I looked where you wrote your 3 eqns and they look all right. I've never seen the notation of how you labeled these equations on the left side, but that's just a label. I would label those Vs as V0 to make it clear those are V0s. But everything looks right.

Let me ask you a question. If you took that first point and called it 0 would that change the physics?