A uniform circular plate of radius 15 cm has a circular hole of radius 3 cm cut out of it. The center of the plate is at the origin of the coordinate system and the center of the hole is located along the x axis a distance 5 cm from the origin.
(a) What is the position of the center of mass of the plate with the hole in it?
(b) If the mass per unit area of material is 5 g/cm2, what is the mass of this object?