4. A mounting is fabricated by removing a paraboloid cavity (formed by rotating a parabola about its axis) from a cylinder of metal with a density of 7.99g/cm3. Dimensions are shown in the figure to the right. (a) Let us set up x - and y-axes such that the centre of the bottom of the mounting is the origin, y is height, and x is horizontal distance from the origin. Then the equation of the parabola is y=9x2+10 (b) The mass of this mounting is g