Last modified on 25 July 2008, at 17:55

Fundamentals of Transportation/Sight Distance/Solution

TProblem
Problem:

You see a a body lying across the road and need to stop. If your vehicle was initially traveling at 100 km/h and skids to a stop on a 2.5% upgrade, taking 75 m to do so, what was the coefficient of friction on this surface?

Example
Solution:


d_b  = \frac{{\left( {100*\left( {\frac{{1000}}{{3600}}} \right)} \right)^2  - \left( 0 \right)^2 }}{{2*\left( {9.8} \right)*\left( {f + 0.025} \right)}} = 75m
\,\!


\left( {f + 0.025} \right) = \frac{{\left( {27.78} \right)^2 }}{{2*\left( {9.8} \right)*75}}
\,\!


f = 0.50
\,\!