You need to supply a picture. It depends on the shape of this arm.
1. The problem statement, all variables and given/known data
Center of gravity for a shape T both arm are 60mm long and 6mm wide.
2. Relevant equations
dont know the equation but seeing as there is no wieght involved am guessing the formula isnt that hard. a discription of the formula and how to use it would help alot
3. The attempt at a solution
if both arms are 60mm and 6mm wide shouldent the center og gravity be where the to arms connect?
where f(x) is the total height or extent in y direction at point x. The y coordinate is found by changing to y and f(y) and taking the integral along the y-axis.
For a standing T the CoG x-coordinate lies midway(x-wise) of the top bar due to symmetry. Let y=0 be at the bottom point of the T, then the CoG y-coordinate of your T is found through
Thus, for your standing T the center of gravity is located at x=0,y=46.5mm, when the bottom tip of the T is put to (0,0)...
This can probably also be done without integrals by exploiting the geometry of the T...