R. Simmons is planning to build a log-cabin style beach house in Crescent Beach, Florida. She wants to make the strongest rectangular cross section 15 feet long ridge beam from this 18 inch diameter white oak log. a) Determine the base and height dimensions of the optimum cross section. (Hint: think section modulus, S) b) Using the cross section from a) and an allowable tensile stress of 1000 psi, what is the maximum allowable uniform distributed load intensity w that this beam would support with simple supports at the ends