So a friend of a friend calls me with this Cal. I. prob. I try to figure it out and get stuck. I have already told her that I don't know how to solve it. Now I am reallllyy curious on how to solve it. Here it goes:(adsbygoogle = window.adsbygoogle || []).push({});

You have a rectangular beam. Its cross-section has dimensions "l" and "w". The strength of the beam is directly proportional to w^2*l. Now if the beam is cut from a circular log with diameter of 3ft, what are the dimensions of the beam that will make it the strongest?

So I said s(w,l)= k*w^2*l where "s" is the strength. The width must be a little less than 3ft...but here I am just guessing. I know that l*w is proportional to pi*r^2, but I don't know where to go from there. help

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Who else but pf could help me w/this prob.

**Physics Forums | Science Articles, Homework Help, Discussion**