Find the lightest Wshape for the simply supported beam if th

Find the lightest W-shape for the simply supported beam if the allowable bending stress is sigma_allow = 18 ksi. Solve the following logarithmic equations without a calculator: ln (x + 8) - ln x = 3 log_5 (x +2) = log_5 (2x - 1)

Solution

Dear Student Thank you for using Chegg !! a) ln(x+8) - ln(x) = 3 Since ln(a) - ln(b) = ln(a/b) Log properties We get ln(x+8)/(x) = 3 (x+8)/x= e^3 x+8 = xe^3 x(e^3-1) =8 x= 8/(e^3-1) b) log5(x+2) = log5 (2x+1) (x+2) = (2x+1) x=1