Answer:
mass =[tex]\frac{k*a^{3} }{2}[/tex]
COM of arc ([tex]\frac{2a}{3}[/tex],[tex]\frac{2a}{3}[/tex])
Explanation:
By using cylendrical coordinate system find total mass and COM position.
This arc is symmetric about x=y thus COM lies on this line.
Rest is in attachment.