Physics Challenge

In this challenge Hank and I paired up with another group to predict where two wind cars would intersect. First, we used a motion sensor to find the initial velocity and the acceleration of cart D. We tested this three times and then averaged our slopes to get an average acceleration of: .1203 m/s^2.
Our initial velocity was Vi: -.18.We recorded 1m away from the sensor. 
Prediction: In order to make a prediction, we used the formula ∆x=1/2a(∆t)^2+(-.18)(t)
∆x=1/2(.1203)^2+(.18)(t)
We solved that equation to find time and got, 4.3s.
Next, we plugged time back into the equation to find our predicted point of intersection. 
Prediction
The distance we found was 1.072 m. 
Cart D: 1.072 m 
Cart C: 97 cm
Results
Actual Point of intersection: 1.072 m
After we tested our prediction we discovered that it was correct. Therefor, our percent error is 0.