part 1 of 2 A square plate is produced by welding to- gether four smaller square plates, each of side a. The weight of each of the four plates is shown in the figure. (2a, 2a) (0, 2a) 60 N 70 N 70 N 20 N (0,0) (2a, 0) Find the r-coordinate of the center of grav- ity ( as a multiple of a). Answer in units of a. part 2 of 2 Find the y-coordinate of the center of grav- ity (as a multiple of a). Answer in units of a