(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A car travels on a horizontal street, straightforward. In some moment of time (t = 0), having a velocity of 20 m/s, the break is hit. It is required to find the time and traveled distance before the car is still standing. The friction coefficient between the wheels and the street is 0.6.

2. Relevant equations

Newtons 2nd law

3. The attempt at a solution

This is a highschool problem, that means it should be simple enough, but I'm puzzled by how to interpret the break force.

My attempt was: if we assume that the car is moving along the positive x-axis, in the moment when the break is hit, a negative force is applied in addition to the frictional resistance, but the car still moves in the positive direction, so there must be a force which "pushes" it forward. As a result, I get t = 3.33s and s = 120m, but this is wrong.

PS: I tried even differential calculus, and would also like to ask, how one handles

[itex]\int\frac{1}{x}dx[/itex] in the bounds starting from 0 to some number t?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Newtons 2nd law problem - how to interpret the break force

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