320 Solutions Manual
Problem 2.242
The gun tackle shown is operated with the help of a horse. If the horse moves to the right at a constant
speed of
7ft=s
, determine the velocity and acceleration of
B
when the horizontal distance from
B
to
A
is
15 ft
. Except for the part of the rope between
C
and
A
, neglect the fact that some portions are not vertically
aligned. Also neglect the change in the amount of rope wrapped around pulley
C
as the horse moves to the
right.
Solution
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
Dynamics 2e 321
Problem 2.243
The figure shows an inverted gun tackle with snatch block, which
used to be common on sailboats. If the end at
A
is pulled at a speed
of
1:5 m=s
, determine the velocity of
B
. Neglect the fact that some
portions of the rope are not vertically aligned.
Solution
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
322 Solutions Manual
Problem 2.244
In maritime speak, the system in the figure is often called a whip-upon-whip
purchase and is used for controlling certain types of sails on small cutters (by
attaching point
B
to the sail to be unfurled). If the end of the rope at
A
is pulled
with a speed of
4m=s
, determine the velocity of
B
. Neglect the fact that the
segment of the rope between
C
and
D
is not vertically aligned, and assume that
the slope of segment AC is constant.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
Dynamics 2e 323
Problem 2.245
The pulley system shown is used to store a bicycle in a garage.
If the bicycle is hoisted by a winch that winds the rope at a rate
v0D5in:=s, determine the vertical speed of the bicycle.
Solution
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
324 Solutions Manual
Problem 2.246
Letting
✓D50ı
, determine the vertical component of the velocity of
Aif Bis moving downward with a speed vBD3ft=s.
Solution
Referring to the figure at the right, we select a Cartesian coordinate
system with axes
p
and
q
and origin
C
such that
p
and
q
are
Dynamics 2e 325
Problem 2.247
Determine the speed of block
B
if block
A
is sliding down the incline with a
speed
vAD1:5 m=s
while the cord is retracted by a winch at a constant rate
v0D2:5 m=s.
Solution
Referring to the figure at the right, we select a Cartesian coordinate
system with axes
p
and
q
and origin
C
such that
p
and
q
are
326 Solutions Manual
Problem 2.248
Block
A
is released from rest and starts sliding down the incline with an acceleration
a0D3:7 m=s2
.
Determine the acceleration of block
B
relative to the incline. Also, determine the time needed for
B
to
move a distance dD0:2 m relative to A.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
Dynamics 2e 327
Problem 2.249
In the pulley system shown, the segment
AD
and the motion of
A
are not impeded
by the load G. Assume all ropes are vertically aligned.
Determine the velocity and acceleration of the load
G
if
v0D3ft=s
and
a0D1ft=s2.
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
328 Solutions Manual
Problem 2.250
In the pulley system shown, the segment
AD
and the motion of
A
are not impeded
by the load G. Assume all ropes are vertically aligned.
The load
G
is initially at rest when the end
A
of the rope is pulled with the
constant acceleration a0. Determine a0so that Gis lifted 2ft in 4:3 s.
Solution
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.
Dynamics 2e 329
Problem 2.251
A crate
A
is being pulled up an inclined ramp by a winch retracting the cord at a constant rate
v0D2ft=s
.
Letting hD1:5 ft, determine the speed of the crate when dD4ft.
Solution
of McGraw-Hill, and must be surrendered upon request of McGraw-Hill. Any duplication or distribution, either in print or electronic form, without the
permission of McGraw-Hill, is prohibited.