To avoid an accident, a driver steps on the brakes to stop a 1000-kg car traveling at 65km/h. if the braking distance is 35 m, how much force is necessary to stop the car?

Question

Physics

Kendall Poole

21 March, 12:31

To avoid an accident, a driver steps on the brakes to stop a 1000-kg car traveling at 65km/h. if the braking distance is 35 m, how much force is necessary to stop the car?

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Answers (1)

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Judah Conner · Answer 1

First, find the needed acceleration needed for the car to stop from its initial velocity given the distance. This is calculated through the equation,

2ad = Vf² - Vi²

where a and d are acceleration and distance, respectively. Vf and Vi are final and initial velocities, respectively. Substituting the known values,

2 (a) (35 m) = (0 m/s) ² - ((65 km/h) x (1000 m / 1 km) x (1 hr / 3600 s)) ²

The value of acceleration is - 4.66 m/s².

The force needed to stop the car is the product of the mass and the acceleration. The operations gives us an answer of - 4,660 N. We take the positive value, 4,660 N.