# Basic non-rotating accelerating reference frame problem

1. Nov 19, 2013

### MuIotaTau

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

A uniform thin rod of length $L$ and mass $M$ is pivoted at one end. The pivot is attached to the top of a car accelerating at rate $A$. What is the equilibrium value of the angle $\theta$ between the rod and the top of the car?

2. Relevant equations

None in particular?

3. The attempt at a solution

I understand that we can treat the acceleration of the car as a horizontal gravitational field of strength $A$. I attempted to solve the problem via torque balance (taking the torque about the pivot), but the only two forces, gravity and the fictional force, have $\theta$ terms that end up cancelling out. I'm sure this is simple, but honestly moving on is going to problem if I can't even do this problem, haha.

2. Nov 19, 2013

### MuIotaTau

Oh, never mind, totally figured this one out.