SOLUTION: the braking distance between D in feet required to stop a car traveling x miles per hour on dry, level pavement can be approximated by D=1/16x^2 A. calculate the braking distanc

Algebra ->  Length-and-distance -> SOLUTION: the braking distance between D in feet required to stop a car traveling x miles per hour on dry, level pavement can be approximated by D=1/16x^2 A. calculate the braking distanc      Log On


   

Question 965909: the braking distance between D in feet required to stop a car traveling x miles per hour on dry, level pavement can be approximated by D=1/16x^2
A. calculate the braking distance for 20 MPH
calculate the braking distance for 60 MPH.
(round to the nearest tenth)
B.if the braking distance is 25 feet, estimate the speed of the car
Estimated speed is approximately___ MPH
(round to the nearest whole number)
C. use a calculator to solve part (B) numerically.
estimated speed is approximately____MPH
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
.
For 20 mph:
D=%281%2F16%29x%5E2=%281%2F16%2920%5E2%29=1%2F16%28400%29=25ft
ANSWER 1: The braking distance at 20 mph is 25 feet.
.
For 60 mph:
D=%281%2F16%2960%5E2=%281%2F16%293600=225ft
ANSWER 2: The braking distance at 60 mph is 225 feet.
.
If the distance is 25 feet, speed is 20 mph. (See ANSWER 1)
-OR-
D=%281%2F16%29x%5E2
16D=x%5E2
x=sqrt%2816D%29=4%28sqrt%28D%29%29 Plug in value for D and solve.