A study was done to determine a new car's stopping distance when it was traveling at different speeds. The study was done on a dry road with good surface conditions. The results are shown below, along with the graph of a quadratic function that models the data.
Refer to the image showing the Vehicle Stopping Distance graph.
According to the model, if the stopping distance of the vehicle was approximately 180 feet, what was its speed in miles per hour?
30
40
50
60
