Hey guys, im trying to help my mom figure this problem out, Im not an engineer (im a geology major) ha... question will be in text... any help would be greatly appreciated!

Question

anonymous · Answer

A 9" pitch diameter gear on a 3.5" diameter shaft with a 7/8" x 7/8" x 2 7/8" effective length key. Tooth load = 4500 # on gear.

Find: 
the key load #
the key bearing pressure (psi)
the key shear stress (psi)

anonymous · Answer

This is very simple, consult http://www.amazon.com/Design-Machine-Elements-8th-Edition/dp/0130489891 It is around 7 or 8 chapter.