A 1–m–diameter, 2–m–high vertical cylinder is completely filled with gasoline whose density is 740kg/m ³ . The tank is now rotated about its Vertical axis at a rate of 90 rpm, while being accelerated upward at 5m/s ² . 

Determine 

(a) The difference between the pressures at the centers of the bottom and top surfaces and 

(b) The difference between the pressures at the center and the edge of the bottom surface.