Equation Derivation Source - Machinery's Handbook Help 1

[Harr2Plus]

I have Machinery's Handbook, 26th Edition. On page 130 there are equations for the forces generated for bodies on an inclined plane (without and with friction). I would like to know if anyone has a source which shows the derivation of the equations. I contacted Machinery's Handbook and unfortunately they weren't able to cite a reference. The person I corresponded with went back as far as he could in their archives but stated that the equations have been in there a long time. I've tried a couple times to derive the equations but seem to be missing something. Just thought I'd see if anyone has an old textbook or other reference which shows the detailed derivations. Thank you for your help.

 

[drawoh]

Harr2Plus,

Try drawing free body diagrams more carefully than Machinery's Handbook did it. The geometry is fairly obvious. You should be able write the equations directly by observation.

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JHG