Physics banking problems w\ friction.

[JeremyWsmith]

Homework Statement

A 1200-kg car rounds a curve of radius 70m banked at an angle of 12 degrees. If the car is traveling at 90km/h, will friction force be required? If so, how much and in which direction?

Homework Equations

mv^2/r = Fc

The Attempt at a Solution

90km/h = 25m/s

Fc = Fnx + uFny
mv^2/r = mgsin12 + u9.8cos12

25^2 = 9.8sin12 + u9.8cos12

u=.72; The coefficient of friction .72 and the force of friction will be perpendicular to the normal force.

Can someone confirm that this is the correct answer?

 

[Andrew Mason]

You have a few errors in writing it out, but your answer is correct. You have not explained why friction is required.

AM