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

Answer 1

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.