At an accident scene on a level road, investigators measure a car's skid mark to be 58 m long. It was a rainy day and the coefficient of friction was estimated to be 0.46. Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes.

Answer 1

Well, friction force is mg*mu(greek letter)

That has to equal m*a
a=g*mu a=(9.8)(.46)=4.508

Vfinal^2=0=Vinitial^2-2*a*d
solve for Vinitial
Vinitial^2=2ad=2(4.508)(58)=522.928
Vinitial=sqr rt(522.928)=22.86761903m/s