The stopping distance d of a car in feet is related to the speed in mph by the equation d(s)=.02s^2+1.1s

Question

Calculate the speed when your stopping distance is:
1.) 51ft
2.) 315.12ft

Answer 1

You must solve two quadratic equations.

0.02 s ^ 2 + 1.1 s = 51

and

0.02 s ^ 2 + 1.1 s = 315.12

If you don't know how solve equations in google type:

quadratic equation online

When you see list of results click on:

Free Online Quadratic Equation Solver:Solve by Quadratic Formula

When page be open in rectangle type:

0.02 s ^ 2 + 1.1 s = 51

and click option: solve it!

You wil see solution step-by-step

Then type:

0.02 s ^ 2 + 1.1 s = 315.12

and click option: solve it!

Remark:

Speed Can't be negative.

You must use only positive solutions.