Generally, final design results are rounded to or fixed to three digits because the given data cannot justify a greater display. In addition, prefixes should be selected so as to limit number strings to no more than four digits to the left of the decimal point. Using these rules, as well as those for the choice of prefixes, solve the following relations:
(a) σ = M/Z, where M = 200 N .m and Z = 15.3 x 103 mm3.
(b) σ = F/A, where F = 42 kN and A = 600 mm2.
(c) y = Fl3/3E I , where F = 1200 N, l = 800 mm, E = 207 GPa, and I = 64 x 103 mm4 .
(d) θ = Tl/GJ , where J = πd4/32, T = 1100 N .m, l = 250 mm, G = 79.3 GPa, and d = 25 mm. Convert results to degrees of angle