- #1

- 13

- 1

## Homework Statement

What is the coefficient of friction between the train and the track, given that the train has 20,000 kg and is going at velocity of 26m/s. Note that when the train conductor saw a pedestrian he started braking and also the distance between the pedestrian to the train is 500m

Other given information:

X= 500m

A= -.676 ( because he was stopping the train)

braking force is -13520 N

## Homework Equations

μ

_{k}N=F

_{k}

N means normal force in this case[/B]

## The Attempt at a Solution

So at first I tried using the simple friction formula and tried isolating the coefficient of friction so that i would have ----------- μ=Nf---------- but i have everything except friction force. So i then thought from that I thought i can just divide a and m to get the force, which in turn is the friction force. Overall i am not sure if this is correct because i thought you can just divide the breaking force and the mass for the friction force. It's either one or the other, although i am not completely sure ))