Name
Period
Date
Dynamics Worksheet 1
Work all problems symbolically and only use numbers in the last step.
1. A ball of weight W hangs in equilibrium from a system of strings as in the diagram
above. The cable at right exerts a 30. N force.
40.
30. N
W
a. On the dot below, draw
and label the forces (not
components) that act on
the point where the strings
come together.
b. Determine the weight of the ball, W. If you need
to draw anything besides what you have shown
in part (a) to assist in your solution, use the
space below. Do NOT add anything to the figure
in part (a).
Dynamics Worksheet 1
page 2
55. kg
10. kg
2. Consider the Modified Atwood’s Machine in the diagram above.
a. On the system figure below, draw a b. What force of static friction between
force diagram of the system as a
the box and the surface is required for
whole.
the system to stay at rest?
c. Draw a separate force diagram for
each mass.
d. What is the tension in the string?
3. If the force of kinetic friction between the 150. N box and the surface is 75 N , what
mass must be placed on the end of the string so that the system will move at
constant velocity? Begin by drawing the needed force diagram(s).
150. N
Constant
Velocity
m?
Dynamics Worksheet 1
page 3
30.
FT2
FT1
FT3
8.0 N
b. If the ball weighs 8.0 N , what are the tensions
in the three ropes? If you need to draw
anything besides what you have shown in part
(a) to assist in your solution, use the space
below. Do NOT add anything to the figure in
part (a).
4. a. The system above is at
rest. On the dot below,
draw and label the forces
(not components) that act
on the point where the
strings come together.
m
200. N
35
5. In the system above the pulley and ramp are frictionless and the block is at rest.
a. Draw and label the forces (not components) that act on the system.
m
Dynamics Worksheet 1
page 4
b. What is the mass of the block on the ramp? If you need to draw anything
besides what you have shown in part (a) to assist in your solution, use the space
below. Do NOT add anything to the figure in part (a).
6. A 5.0 kg box is being pulled by a cable at a constant velocity
up a 30. ramp with some friction as shown.
a. Draw and label the forces (not components) that act on
the box.
60. N
30.
b. If the tension in the cable is 60. N , how much friction acts upon the box? If you
need to draw anything besides what you have shown in part (a) to assist in your
solution, use the space below. Do NOT add anything to the figure in part (a).
c. What normal force does the ramp exert upon the box?