# Homework Help: Help with complex friction problem

1. Oct 27, 2005

### newcool

Help with complex circular motion + friction problem

The scenario is this:
You are in a car that is at rest in a circle of radius r. The car then accelerates to some max speed v. There is also friction that restricts the car to the max speed. At what angle is the max speed v reached? (calculus is involved)
I am stuck in a bind since you can't use any of the kinematics equations
This is what I did so far:
a = sqrt( (v^2/r)^2 + (dv/dt)^2)
F_net = m( sqrt( (v^2/r)^2 + (dv/dt)^2)
I am NOT looking for the answer, just some pointers on how to proceed.

Last edited: Oct 27, 2005
2. Oct 27, 2005

### newcool

Sorry, here is the latex of my work:
$$A^2=a_{tan}^2+a_{rad}^2$$
$$A=\sqrt( (v^2/r)^2+ (\dot {v})^2 )$$
$$F_{net} = m*\sqrt( (v^2/r)^2+ (\dot {v})^2 )$$
Any ideas on how to proceed would be appreciated
Thanks!

Last edited: Oct 27, 2005
3. Oct 29, 2005

### newcool

Solved this on my own. Mods please delete

Thanks