Thread: Rectangular Beam

The maximum safe load that a rectangular beam can support varies directly with the width w and the square of the height h and inversely with the length L of the beam. A 6-foot-long beam that is 2 inches high and 4 inches wide has a maximum safe load of 1000 pounds.

(a) What is the maximum safe load for a 10-foot-long beam that is 4 inches high and 4 inches wide?

(b) How long should a 4 inch beam be to safely support a 6000-pound load?

Originally Posted by sologuitar

The maximum safe load that a rectangular beam can support varies directly with the width w and the square of the height h and inversely with the length L of the beam.

Translating this directly into an equation, I get



where is a proportionality constant that you have to determine from the data you've been given. That is, they've given you M, w, h, and L in one case, and you have to figure out for that case.

Once you know , you can use it to solve for any of the unknown situations.

Originally Posted by Haversine

Translating this directly into an equation, I get



where is a proportionality constant that you have to determine from the data you've been given. That is, they've given you M, w, h, and L in one case, and you have to figure out for that case.

Once you know , you can use it to solve for any of the unknown situations.

Thanks for the tips. I can take it from here.