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

a. A 49,000 kg locomotive is traveling at 11 m/s when its engine and brakes both fail. How far will the locomotive roll before it comes to a stop?

_____m

b. Determine the stopping distance if the locomotive had the same initial velocity but was "low on diesel" so its mass was only 35,000 kg.

______m

2. Relevant equations

Fr = µr x n

F = ma

Max = F1 - F2

May = F1 - F2

3. The attempt at a solution

To start off I drew a force diagram which showed thre forces; normal force going up, weight going down, and friction going in the opposite direction of the car. I found weight by multiplying the mass by 9.8, which ended up being 408200. I know that this must also be the amount for the normal force. But, now I'm at a standstill. I don't think the coefficients have anything to do with the problem but I'm starting to second guess myself. Am I able to use the mass and weight to figure out the decceleration of the car so that I will be able to use the velocity to find the distance? Thank you in advance!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Car rolling and Friction

**Physics Forums | Science Articles, Homework Help, Discussion**