PROBLEM 12.62 (Continued)
PROBLEM 12.63
Knowing that the coefficients of friction between the component I and member BC of the mechanism of
Problem 12.62 are
0.35
s
and
0.25,
k
determine (a) the maximum allowable constant speed
B
v
if the
component is not to slide on BC while being transferred, (b) the values of
for which sliding is impending.
PROBLEM 12.63 (Continued)
PROBLEM 12.63 (Continued)
PROBLEM 12.64
A small 250-g collar C can slide on a semicircular rod which is made to rotate about
the vertical AB at a constant rate of 7.5 rad/s. Determine the three values of
for
which the collar will not slide on the rod, assuming no friction between the collar
and the rod.
PROBLEM 12.65
A small 250-g collar C can slide on a semicircular rod which is made to rotate about
the vertical AB at a constant rate of 7.5 rad/s. Knowing that the coefficients of
friction are
s = 0.25 and
k = 0.20, indicate whether the collar will slide on the rod if
it is released in the position corresponding to (a)
= 75, (b)
= 40. Also,
determine the magnitude and direction of the friction force exerted on the collar
immediately after release.
PROBLEM 12.65 (Continued)
PROBLEM 12.66
An advanced spatial disorientation trainer allows the cab to rotate around
multiple axes as well as extend inwards and outwards. It can be used to
simulate driving, fixed wing aircraft flying, and helicopter maneuvering. In
one training scenario, the trainer rotates and translates in the horizontal plane
where the location of the pilot is defined by the relationships
10 2cos 3
rt
and
2
0.1 2tt
, where r,
and t are expressed
in feet, radians, and seconds, respectively. Knowing that the pilot has a mass
of 175 lbs, (a) find the magnitude of the resulting force acting on the pilot at
t= 5 s (b) plot the magnitudes of the radial and transverse components of the
force exerted on the pilot from 0 to 10 seconds.
PROBLEM 12.66 (Continued)
PROBLEM 12.67
An advanced spatial disorientation trainer is programmed to only rotate
and translate in the horizontal plane. The pilot’s location is defined by the
relationships
81
t
re
and
2/ sin 2t
, where r, and t
are expressed in feet, radians, and seconds, respectively. Determine the
radial and transverse components of the force exerted on the 175 lb pilot at
t = 3 s.