# Reaction force of freely rotating rod

1. Aug 6, 2012

### rruben

Hi guys!

I'm working some problems for our exam in a few weeks and there are a few problems we are unable to solve.

One of them is: "A homogenous rod is free to rotate without friction around one of it's ends. Find the reaction force in function of the position of the rod."

As you can see the question is very vague, we've tried to do something with Euler's angles and equations of motion but cannot get to a solution. Any input or help would be greatly appreciated!

Thanks

2. Aug 6, 2012

### Staff: Mentor

Maybe you should calculate the force on the fixed point due to gravity and movement of the rod. If you can assume zero movement, it is just a function of the position, otherwise the angular velocity is relevant, too.

3. Aug 7, 2012

### rruben

We think that may be right but the difficulty is how to go about something like this, not assuming zero movement of course.

4. Aug 7, 2012

### Staff: Mentor

Calculate it with zero movement, add the centripetal force.