a only.

(8) LetW be the region in R3 inside x2 + y2 = 1 that is below 2 = 3 x2 y2 and abovez = y/x2 + y2 . More precisely, W={(x,y,z):x2+y231,'/x2+yZSZs3x2y2}. (a) Sketch the region W. (b) Consider a uid of constant density \"(x, y, z) = 5 (measured in g/in3) owing with velocity 006, y, Z) = (3x)/2 e12, y3 xcos(z), x3 y3) measured in in/s. Use the appropriate version of Stokes theorem to nd the total amount of uid (in grams) that crosses the boundary of W owing in the inward direction after 2 seconds. (c) If you did things correctly, the answer you got in (b) is negative. What is the physical interpretation for this negative sign