Can somebody point me towards a reference which will let me solve the following problem:
I've got a beam of 5/8" thick by 3-3/4" deep walnut, 28 inches long, supported only at the ends. There is a 150 lb point load at center span. What is the deflection of the beam?
Stated this way, it sounds like a civil engineering problem, but of course what I'm really trying to do is figure out if the rails on a bench I'm building are big enough. I know a true craftsman would just look at it and say, "yeah, that looks strong enough", but the engineer in me us just itching to crunch numbers.