Den Hartog’s Mechanics

A web-based solutions manual for statics and dynamics

Problem 12

The point and forces of interest are laid out as follows:

Taking clockwise as positive, the moment about the pulley center, O, is

M_O = 200 \cdot 8 - 100 \cdot 8 - 100\cdot 6 = 200\:\rm{lb}\cdot\rm{in}

which is the answer to part (a). We could do essentially the same thing to get the moment about point A, but just to throw in a bit of variety, we’ll start by taking the static equivalent of the forces at O

and transforming the moment to point A:

M_A = M_O - 100 \cdot 8 = 200 - 800 = -600\:\rm{lb}\cdot \rm{in}

or 600\:\rm{lb}\cdot \rm{in} counterclockwise. This is the answer to part (b).

Problem 13Problem 11

Last modified: January 22, 2009 at 8:32 PM.