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A 14,700 N car is traveling at 25 m/s. The brakes are applied suddenly, and the car slides to a stop, as shown in the picture link below. The average brakeing force between the tires and the road is 7,100 N. How far will the car slide once the brakes are applied?

This problem is complicated and it is giving me trouble.
Please help me to understand it to solve.

2007-01-26 13:38:47 · 2 answers · asked by swimmertommy 1 in Science & Mathematics Physics

I forgot the picture link!
* Picture link: http://img143.imageshack.us/img143/4066/scan0001gd0.jpg

2007-01-26 13:44:10 · update #1

2 answers

The acceleration is g*F/W = 9.8*7100/14700 = 4.7333 m/s²

Distance = V²/2a = 25²/(2*4.7333) = 66.02 m

firefly used the weight, not the mass, in his 1st eq.....

2007-01-26 16:12:30 · answer #1 · answered by Steve 7 · 1 0

use F=ma to get the decelleration:
7100 = 14700*a
so a = 7100/14700

Now, use the equation of motion:
vf^2 = vi^2 + 2as
to get a
where vf^2 = 0
vi^2 = 25*25

so s = 25*25/(2*7100/14700) = 647 meters

2007-01-26 14:11:18 · answer #2 · answered by firefly 6 · 0 0

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