A force of 30 N is required to hold a spring that has been stretched from its natural length of 0.2 m to a length of 0.25 m. How much work is done in stretching the spring from 0.25 m to 0.3 m. OR An aquarium 2 m long, 1 m wide, and 3 m deep is full of water with density 1000 kg/m3. Find the hydrostatic force and the hydrostatic pressure on the bottom of the aquarium. (Use g = 9.8 m/s2) (Hint: Integration is not required.) 5) Find the area of the surface generated by revolving the curve y = x3 about x-axis on the interval [0, 1]. 6) Find a parametrization for the curve. the line segment with endpoints (6, 2) and (9, 11).