Fig. 45
42 Aptitude Test Problems in Physics
AB = 2/. A load of mass m is suspended at
the hinge C.
Determine the minimum force Fnon ap-
plied to the hinge D for which the middle
rod remains horizontal.1.88. A hexagonal pencil placed on an in-
clined plane with a slope a at right angles
to the generatrix (i.e. the line of intersec-
tion of the plane and the horizontal surface)
remains at rest. The same pencil placed
parallel to the generatrix rolls down the
plane.
Determine the angle cp between the axis
of the pencil and the generatrix of the in-
clined plane (Fig. 46) at which the pencil
is still in equilibrium.
1.89. A homogeneous rod of length 2/
leans against a vertical wall at one end and
against a smooth stationary surface at an-
other end.
What function y (.x) must be used to de-
scribe the cross section of this surface for
the rod to remain in equilibrium in any
position even in the absence of friction?
Assume that the rod remains all the time