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

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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) About Me  (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.