Missing Parts
Here are the formulae to work out the thinking distance and the braking distance for a car traveling at V miles per hour.
Thinking distance = V feet
(a) A car is traveling at 70 miles per hour. What is the total stopping distance for this car? feet
(b) A different car is traveling so that its braking distance is 125 feet. How fast is the car traveling? miles per hour
Answer:
(a)2520 feet
(b)50mph
Explanation:
Total Stopping Distance = Thinking Distance + Braking Distance
Given that for a car traveling at V miles per hour:
Thinking distance = V feet
We have:

(a)V=70 miles per hour

The total stopping distance for a car traveling at 70 miles per hour is 2520 feet.
(b)
Braking Distance = 125 feet
Therefore:

A car with a braking distance of 125 feet is traveling at a speed of 50mph.