Question

The graph shows the distance, in feet, required for a car to come to a full stop if the brake is fully applied and the car was initially traveling x miles per hour.

A graph shows speed (miles per hour) labeled 10 to 100 on the horizontal axis and stopping distance (feet) on the vertical axis. A line increases from 0 to 60.

Which equation can be used to determine the stopping distance in feet, y, for a car that is traveling x miles per hour?

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Answer 1

I don't have enough information to pick the correct equation. Could you either

- upload the graph image, or
- tell me two points on the line (for example "at 20 mph the stopping distance is 40 ft and at 60 mph it's 180 ft"), or
- paste the four answer choices shown?

If you want the general method:
- If the graph is a straight line through the origin, the equation is y = mx where m = (rise)/(run) from any two points.
- If the graph is a parabola (stopping distance usually varies with speed squared), the equation is y = kx^2 where k = y/x^2 for any point on the curve.

Give one of the requested details and I’ll find the specific equation.