The stopping distance, d, of a car after the brakes are applied varies directly as the square of the speed, s, of the car. If a car traveling at a speed of 40 miles per hour can stop in 80 feet, what is the stopping distance of a car traveling at 55 miles per hour
We can use the formula for direct variation:
d = k s^2
where k is the constant of proportionality. To find k, we can use the given information for the first car:
80 = k 40^2
k = 80/1600
k = 0.05
Now we can use this value of k to find the stopping distance of the second car:
d = 0.05 55^2
d = 150.25 feet
Therefore, the stopping distance of the car traveling at 55 miles per hour is 150.25 feet.