math

posted by .

The stopping distance of a car after the brakes are applied varies directly as the square of the speed r. If a car traveling 80 mph can stop in 360ft, how many feet will it take the same car to stoop when its traveling 50 mph?

• math -

d = k r^2
360 = k (80)^2
k = 360/80^2

d = [360/80^2] * 50^2

d = 360 (25/64)

d = 141 ft

Similar Questions

1. algebra

The stopping distance d of a car after the brakes have been applied varies directly as the square of the speed r. if the car traveling 70mph cab stop in 270ft, how many feet will it take the same car to stop when it 1s traveling 50 …
2. math

The stopping distance d of a car after tehe brakes are applied varies directly as the square of the speed r. If a car traveling 50 mph can stop in 140 ft. How many feet will it take the same car to stop when it is traveling 70 mph?
3. Math help

9). Hooke’s Law. The distance d when a spring is stretched by a hanging object varies directly as the weight w of the object. If the distance is 29 cm when the weight is 4 kg what is the distance when the weight is 9 kg?
4. algebra 2

The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r. If a car travelling 70mph can stop in 270ft, how many feet will it take the same car to stop when it is travelling 60mph?
5. algebra 2

The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r. If a car travelling 70mph can stop in 270ft, how many feet will it take the same car to stop when it is travelling 60mph?
6. algebra

The stopping distance d of a car after the brakes are applied directly as the square of the speed r. If a car traveling 80mph can stop in 360ft, how many feet will it take the same car to stop when it is traveling 90mph
7. algebra

the stopping distance d of a car after the brakes are applied varies directly as the square of the speed r if a car travelling 80mph can stop in 360ft, how many feet will it take the same car to stop when it is travelling 70mph
8. algebra

The stooping distance d of a car after the brakes are appied varies directly as the square root of the speed r. If a car traveling 40mph can stop in 90 ft., how many feet will it take the same car to stop when it is traveling 60 mph.
9. math

The stopping distance d of a car after the brakes have been applied varies directly as the square of the speed r. If a car traveling 40 mph can stop in 100 ​ft, how fast can a car travel and still stop in 256 ​ft?
10. algebra

The stopping distance d of a car after the brakes have been applied varies directly as the square of the speed r. If a car traveling 50 mph can stop in 250 ​ft, how fast can a car travel and still stop in 90 ​ft?

More Similar Questions