SOLUTION: PHYSICS—ENGINEERING For a car traveling at a speed of v miles per hour, under the best possible conditions the shortest distance d necessary to stop it (including reaction time) is

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: PHYSICS—ENGINEERING For a car traveling at a speed of v miles per hour, under the best possible conditions the shortest distance d necessary to stop it (including reaction time) is      Log On


   



Question 812113: PHYSICS—ENGINEERING For a car traveling at a speed of v miles per hour, under the best possible conditions the shortest distance d necessary to stop it (including reaction time) is given by the formula d = 0.044V^2 + 1.1v, where d is measured in feet. Estimate the speed of a car that requires 165 feet to stop in an emergency.
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
165 = 0.044v^2 + 1.1v
---
0.044v^2 + 1.1v - 165 = 0
---
the above quadratic equation is in standard form, with a=0.044, b=1.1, and c=-165
---
to solve the above equation using the quadratic formula, plug this:
0.044 1.1 -165
into this: https://sooeet.com/math/quadratic-equation-solver.php
---
the roots (solutions) of the above quadratic equation are:
50
-75
---
in this context, the negative root (-75) doesn't make sense, so use the positive root (50)
---
Answer:
50 mph
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Convert fractions, decimals, and percents:
https://sooeet.com/math/fraction-decimal-percent.php
---
Calculate and graph the linear regression of any data set:
https://sooeet.com/math/linear-regression.php