Homework Help: Car Wheelie

1. Mar 28, 2010

msg558

1. The problem statement, all variables and given/known data

Equations of motion are to be derived to describe the motion of a car(rear wheel drive) at rest which then accelerates to perform a wheelie.

Basically, I need equations of motion that would help me determine the force that the rear wheels exert on the car in order to cause a wheelie.

2. Relevant equations

3. The attempt at a solution

I have simplified the problem by assuming the car is a rectangle sliding on a horizontal surface with a horizontal force acting where the rectangle meets the surface.

This leads to the EOMs that I THINK are correct

$$$F = m \ddot{x}$$$
$$$N - mg = m \ddot{y}$$$
$$$-mgLcos(\theta ) + NLcos(\theta ) = I \ddot{\theta }$$$

I made a guess that I should sum moments about the edge where the force is applied.

The problem that I am having is that the equation for rotation contains 0 x-direction force terms, but it is obviously the x acceleration which causes the rotation.