Section 2.5, problem 228 For the following exercises, find the mass of the one-dimensional object. 228. A ruler that is 12 in. long (starting at x = 5) and has a density function of p(x) = In(x) + (1/2) x2 oz/in. Section 2.5, problem 232 For the following exercises, find the mass of the two-dimensional object that is centered at the origin. 232. A jar lid of radius 3 in. with density function p(x) = In(x + 1)