# A little question

1. Jul 4, 2009

### Dweirdo

Hi

if i have lets say a rod swinging on a pivot, and i calculate the moment of inertia around the axis, which is the pivot, and i get the angular acceleration.
now lets say i want to the the same around the other end of the rod, but the thing is that in the lab F.O.R it is moving around the pivot, although in the F.O.R of the other end of the rod, the pivot moves around that end, so why can't i make the same equations, and substitute angular acceleration with the one that i got before, and then find the net torque,
i mean, because it's an accelerated f.O.R i need to be careful, and add some factious forces and stuff, so how do i deal with that?
thanks
Dweirdo

2. Jul 4, 2009

### tiny-tim

Hi Dweirdo!

Yes, you can do that … see, for example, http://en.wikipedia.org/wiki/Fictitious_force

3. Jul 4, 2009

### Dweirdo

Hi Tim,and thanks
I've looked it p, but which one of these should i use in my case:
1)Rotating observer
2)Rotating coordinate systems

and what is this symbol:Ω?
thanks :)
Dweirdo

4. Jul 4, 2009

### tiny-tim

Theyr'e the same aren't they?

(and Ω is angular velocity)

5. Jul 4, 2009

### Dweirdo

idk they come up as 2 different sectors :P oh well
and why the hell they have to make things so complicated , omega should be angular velocitY!!!!!!!! :P
thanks again,
dweirdo

6. Jul 4, 2009

### cosmo123

never mind, silly question :(

7. Jul 5, 2009

### Dweirdo

Frame of reference-F.O.R :P

8. Jul 5, 2009

### tiny-tim

Ω

Hi Dweirdo!

Ω is capital ω … see http://en.wikipedia.org/wiki/Greek_alphabet

(that's partly why someone with a sense of humour made Ω the symbol for ohm! )

9. Jul 5, 2009

### Dweirdo

haha cool :) still omega sounds way smoother :P
i still think they just try to make things complicated :)
*goes to study greek alphabet*
Dweirdo