\fdO'^ - Old Forge Coal Mines

214 STRENGTH OF MATERIALS.
drawn. Parallel to the rays are drawn the lines of the
equilibrium polygon a b c d g a. The closing line g a'\%
found to be parallel to Pi. Consequently, 0-1 is the left
reaction and 1-3 the right reaction, the former being 6 tons
2
Scale of forces 1=5 torts.
Scale of distance 1^5^
Fig. 48.
and the latter 3 tons. The shear diagram is drawn in the
usual manner ; it has the peculiarity of being zero between
F^ and F^.
(574) The maximum moment occurs when the shear
line crosses the shear axis. In the present case the shear
line and shear axis coincide with s t, between F and F ;
hence, the bending moment is the same (and maximum) at
F^ and i%, and at all points between. This is seen to be true
from the diagram, since k h and b c are parallel. Ans.
{Jb) By measurement, the moment is found to be 24 X 12 =
288 inch-tons. Ans.
(r) 288 X 2,000 = 576,000 inch-pounds. Ans.