# Using torque about one point to get torque about a different point

1. Nov 10, 2011

### rachaelvicto

Hello All,
I'm not a physicist so this may be very straightforward, I'm just not seeing it. If anyone can help it would be greatly appreciated.

What I would like to do is take an equation for torque for an object about one point and use this result to get the torque for the same object about a different point. I am trying to calculate the forces and torque for an L shaped dielectric in a gaussian profile beam using ray optics. As I increase the length of the lower leg on the L, I want to see how this affects the torque balance. If I calculate the torque about the focal point, viola, nice clean answer. It is much easier to think about the problem physically for torques calculated about the center of mass for the dielectric. The actual calculation of the torque about the center of mass is, however, kind of obscenely complicated.

Any ideas?
Thanks guys.