*5.48 and *5.49 Determine by direct integration the centroid of the area shown. 5.50 Determine the centroid of the area shown in terms of a. 5.51 Determine the centroid of the area shown when a = 4 in. 5.52 Determine the volume and the surface area of the solid obtained by rotat- ing the area of Prob. 5.1 about (a) the line x = 240 mm, (b) the y axis. 5.53 Determine the volume and the surface area of the solid obtained by rotating the area of Prob. 5.7 about (a) the x axis, (b) the y axis. a Fig. P5.50 and P5.51 X