# physics

If a car is travelling at 60. miles per hour and the brakes are applied so that it accelerates at -15.0 ft/s2, how many feet will it take to stop?

i realize i am posting a lot of questions, but i don't understand them!

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1. First convert 60 mph to 88 ft/s.

During braking, the average velocity will be 1/2 * 88 = 44 ft/s

The time required to stop will be
(88 ft/s)/15 ft/s^2 = 5.87 s

Stopping distance = average speed x time

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2. that tells me the time, but how do i find the number of feet?

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