posted by Ashley .
The maximum safe load of a rectangle beam varies jointly as its width and the square of its depth and inversely as the length of the beam. If a beam 8.00 in. wide, 11.5 in. Deep, and 16.0 ft long can safely support 15.000 lb, find the safe load for a beam 6.50 in. Wide, 13.4 in. Deep, and 21.0 ft long made of the same material.
SL=15 * (6.5/8) * (13.4/11.5)^2*(16/21)= 12.61 Lbs.