Question

Assume that the stopping distance of Van varies directly with the square of the speed. A Van travelling 20 miles per hour can stop in 70 feet. If the van travelling 24 miles per hour what is the stopping speed?

Answer 1

stopping distance = a speed^2

20 milles/h

70 feet

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replacing the data

stopping distance = a speed^2

70 ft = a* 20^2 miles/ h

as it varies directly we look for the constant of proportionality

a = 70 / 20^2 = 7/2

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