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PROBLEM 15.73
A juggling club is thrown vertically into the air. The center of
gravity G of the 20 in. club is located 12 in. from the knob.
Knowing that at the instant shown G has a velocity of 4 ft/s
upwards and the club has an angular velocity of 30 rad/s
counterclockwise, determine (a) the speeds of Point A and B,
(b) the location of the instantaneous center of rotation.
PROBLEM 15.74
At the instant shown during deceleration, the velocity of an
automobile is 40 ft/s to the right. Knowing that the velocity of the
contact point A of the wheel with the ground is 5 ft/s to the right,
determine (a) the instantaneous center of rotation of the wheel,
(b) the velocity of point B, (c) the velocity of point D.
PROBLEM 15.75
A helicopter moves horizontally in the x direction at a speed of
120 mi/h. Knowing that the main blades rotate clockwise with an
angular velocity of 180 rpm, determine the instantaneous axis of
rotation of the main blades.
PROBLEM 15.76
A 60-mm-radius drum is rigidly attached to a 100-mm-radius drum as
shown. One of the drums rolls without sliding on the surface shown, and a
cord is wound around the other drum. Knowing that end E of the cord is
pulled to the left with a velocity of 120 mm/s, determine (a) the angular
velocity of the drums, (b) the velocity of the center of the drums, (c) the
length of cord wound or unwound per second.
PROBLEM 15.77
A 60-mm-radius drum is rigidly attached to a 100-mm-radius drum as shown.
One of the drums rolls without sliding on the surface shown, and a cord is
wound around the other drum. Knowing that end E of the cord is pulled to
the left with a velocity of 120 mm/s, determine (a) the angular velocity of the
drums, (b) the velocity of the center of the drums, (c) the length of cord
wound or unwound per second.
PROBLEM 15.78
The spool of tape shown and its frame assembly are pulled upward at a
speed
750
A
v=
mm/s. Knowing that the 80-mm-radius spool has an angular
velocity of 15 rad/s clockwise and that at the instant shown the total
thickness of the tape on the spool is 20 mm, determine (a) the instantaneous
center of rotation of the spool, (b) the velocities of Points B and D.
PROBLEM 15.79
The spool of tape shown and its frame assembly are pulled upward at a
speed
100 mm/s.
A
v=
Knowing that end B of the tape is pulled downward
with a velocity of 300 mm/s and that at the instant shown the total thickness
of the tape on the spool is 20 mm, determine (a) the instantaneous center of
rotation of the spool, (b) the velocity of Point D of the spool.
PROBLEM 15.80
The arm ABC rotates with an angular velocity of 4 rad/s
counterclockwise. Knowing that the angular velocity of the
intermediate gear B is 8 rad/s counterclockwise, determine
(a) the instantaneous centers of rotation of gears A and C,
(b) the angular velocities of gears A and C.
PROBLEM 15.80 (Continued)
Gear C:
2
1.2 0.8
C
vv
ω
−−
= =
PROBLEM 15.81
The double gear rolls on the stationary left rack R. Knowing that the rack on the
right has a constant velocity of 2 ft/s, determine (a) the angular velocity of the
gear, (b) the velocities of Points A and D.
