**PURPOSE: **To verify the equation for torques when the center of mass is outside the object.

**DESCRIPTION: **A bracket is bent into a right triangle with arms of length *a* and 2*a*, and suspended from the end of the small arm as photographed. What is the angle of repose *r* of the small arm with the vertical, at equilibrium?

From the equation of torques,* w*1* x*1 = *w*2 * x*2,

where: *w*1= mg and* x*1= *a*/2 sin *r*,

also: *w*2 = 2mg and *x*2 = *a* cos *r* - *a* sin *r*)

From these, tan *r* = 4/5, and *r* = 38.66 degrees.

**SUGGESTIONS: **

**REFERENCES: ** (PIRA
unavailable.)

**EQUIPMENT: **Right angle bracket, plumb bob, and protractor, pre-assembled as shown.

**SETUP TIME: **None.