SOLUTION: Please help! The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r. If a car traveling 60 mph can stop in 200 ft, how many

Question 334290: Please help!
The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r. If a car traveling 60 mph can stop in 200 ft, how many feet will it take the same car to stop when it's traveling 50 mph?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r. If a car traveling 60 mph can stop in 200 ft, how many feet will it take the same car to stop when it's traveling 50 mph?
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d = k/r^2
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Find "k" using d = 200 when r = 60 mph
200 = k/3600
k = 720000
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Equation:
d = 720,000/r^2
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If r = 50, d = 720,000/50^2 = 1152 ft
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Cheers,
Stan H.
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