sqrt( 30000psi * 8 / (3+0.3/(1-0.3)) / 7.9g/cm^3 / (3.5in)^2

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.