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Circular Motion Workshseets
`Physics, Mr. Kent
Daily Worksheet: Circular Motion #1
Name: ______________________________________
1. Definition of linear: _____________________________________________________
2. We’ve seen linear ______________________, linear ______________________,
linear ______________________ and linear ______________________
3. ________________________________ is the only “thing” in this course so far that
hasn’t been linear. Draw two pictures of non-linear projectile motion:
4. Consider the following diagram:
AB is a ______________________ of circle O
OD is a ______________________ of circle O
ACBDA is the ______________________ of circle O
Formula for circumference of a circle: _____________
Circumference of circle O: ______________________
5. Consider the following diagram:
l1 and l2 are ______________________ of circle O
l3 is a ______________________ of circle O
A chord intersects a circle at ______ points
A tangent intersects a circle at ______ point
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Circular Motion Workshseets
6. Draw a tangent to circle O at each marked point on its circumference.
7. Draw circle O with Diameter AOB, radius OC (3.2 m), Chord DE and tangents to the
circle at points D and E. What is the circumference of circle O? __________________
8. Whenever motion is circular there is an ____________________________________.
This passes through the ________________ of the circle.
9. In circular motion, one trip around the circle is called a ___________________ or a
___________________ and the time required to make that one trip is called the
__________________ (_______).
10.Objects a and b.
How to the radii compare? ___________________
How do the periods compare? ________________
a
b
How to the velocities compare? _______________
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Circular Motion Workshseets
11.Calculate the velocity of the object if it moves at a constant velocity.
v = d/t
d = _____________
t = ______________
v = ______________
12.A model airplane travels at 14.5 m/s at the end of an 0.85 m string. Period? _________
13.A model airplane at the end of a string rotates 100 times each minute. rpm? _________
14.A model airplane at the end of a string rotates 20 times in 15 seconds. rpm? _________
15.A model airplane at the end of a string rotates 75 times in 40 seconds. rpm? _________
16.If the string used to swing a ball over your head breaks then the ball will
travel along the ___________________ to the circle at the _____________ where the
ball resides when the string is cut.
17.At a particular point, the direction of travel of an object in circular motion is along the
__________________ at that point.
18.This means that, even though over time an object in circular motion is travelling in a
______________ at any point it is actually travelling _________________.
19.Draw a ball on a string travelling in a circle. Draw the ball at 3 points and draw the
direction of travel of the ball at each point.
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Circular Motion Workshseets
Physics, Mr. Kent
Class Work: Circular Motion #1
Name: ______________________________________
1. What does “linear” mean? ________________________________________________
2. Draw a ball with linear velocity of 5 m/s.
3. Draw circle O with diameter AOB and radius OC (0.4 m). Circumference? _________
4. Draw circle O with chord DE and tangent FG.
5. Draw circle O with points A, B, C and D on its circumference. Draw the tangent to the
circle at points A – D.
6. Whenever an object is in circular motion, it is travelling around the __________ of its
circular path. This center is on the object’s __________________________________.
7. For each situation, describe the axis of rotation:
a. A person swings a model airplane in a circle over her head: ___________________
___________________________________________________________________
b. A child rides on a horse of a merry go round: _______________________________
___________________________________________________________________
c. Danica Patrick drives around a circular track: _______________________________
___________________________________________________________________
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Circular Motion Workshseets
8. Draw a circle with a radius of 5 m that represents the circular surface of a table that can
be spun circularly. Draw a radius then draw to small objects: Object one 1.5 m from
the axis of rotation and Object two 4 m from the axis. Label all distances from the axis.
The time to complete one revolution is 0.35 s.
a. How far will Object #1 travel in one revolution? ____________
b. How far will Object #2 travel in one revolution? ____________
c. What is the period (T)? _________
d. As the table top rotates, what is the velocity of Object #1? _________ m/s
e. As the table top rotates, what is the velocity of Object #2? _________ m/s
9. A toy airplane travels in a circle at the end of a string at 8.5 m/s, The length of the
string is 0.2 m. How long does it take for the plane to make one rotation? __________
10.A car travels around a circular track with a radius of 80 m. Each 20 seconds, it
completes one trip around the track. What is the car’s velocity? _________ m/s
11.Walking at 4.25 m/s, Linda completes one trip around a circular walking path in 3
minutes and 20 seconds. What is the radius of the track? _______________________
12.One way to measure circular velocity is to do the same as we do with linear velocity:
Use the unit of measure ____________. Another unit of measure, the ______________
per ______________ (________) is also used for circular velocity.
13.A ball on the end of a string makes 50 revolutions in one minute. rpm? ____________
14.A ball on the end of a string makes 50 revolutions in 35 seconds. Minutes: _________
rpm? ____________
15.A ball on the end of a string makes 12 revolutions in 30 seconds. rpm? ____________
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Circular Motion Workshseets
16.A person swings a heavy weight around his body at the end of a rope.
a. Describe the motion of the weight over time: ___________________
________________________________________________________
b. Describe the motion of the weight at a particular instant: __________
________________________________________________________
17.Draw circle O (radius of 45 cm) with point P on the circumference. Presume that an
object travelling along the circle is at point P at noon today and that it makes one trip
around the circle in 0.3 s. Draw the circle and a line representing the velocity of the
object at noon today. Speed in m/s? ___________ Speed in rpm? _____________
18.A 650 kg roller coaster car travels at an unknown velocity at the top of a 35 m high
peak in the frictionless roller coaster track. The car rolls until it is travelling at 1.75 m/s
at an elevation of 45 m. What was the car’s initial velocity? ______________
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Circular Motion Workshseets
Physics, Mr. Kent
Quiz: Circular Motion #1
Name: ______________________________________
A cyclist participating in a race on a circular track with a radius of 40 m travels at a
constant velocity and completes 25 laps in 5 minutes and 50 seconds.
1. Length of one lap:
______________
2. Distance travelled:
______________
3. Velocity (in m/s):
______________
4. Velocity (in rpm):
______________
An 800 kg roller coaster car travels at 2.5 m/s at the top of a peak in its track of
unknown height. The car rolls down the track to a low point (elevation = 0 m) where
it is travelling at 17.25 m/s.
5. What was the initial height? ________________. Show work for partial credit.
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Circular Motion Workshseets
Physics, Mr. Kent
Daily Worksheet: Circular Motion #2
Name: ______________________________________
1. In circular motion, one trip around the circle is called a ________________ or a
__________________ & the time to make that trip is called the _____________ (____)
2. Calculate velocity in m/s: _________________
r = 1.2 m
3. Over time, an object in circular motion moves in a _____________. At any particular
point, however, the object in circular motion moves ___________________ along a
_______________ to the circle.
4. Two names for this velocity in m/s:
a. ______________________________ b. ______________________________
5. A person walking for exercise completes 18 laps of on a circular track in 24 minutes.
rpm? ___________________
6. A fly wheel revolves at a speed of 8,000 rpm. How many revolutions does it make in
45 seconds? _________________
Questions 7 & 8: Multiple objects are placed on a revolving
table at different distances from the axis of rotation.
7. When the table is rotated, how does the time required for the
objects to complete a single rotation compare? Is that time the
same or different for the objects? ______________. So, how
does radius affect rpm? ______________________________
8. How does the distance that an object at the outside of the table travel in a revolution
compare to the distance travelled by an object at the inside? ______________. So, how
does radius affect linear/tangential velocity? __________________________________
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Circular Motion Workshseets
9. Objects have ______________. In slang terms, this means that objects don’t want their
_______________ to change. That is, they don’t want their ______________ or
__________________ to change.
10.A _______________ can overcome an object’s ________________ in two ways:
a. _____________________________________________
b. _____________________________________________
11.At any particular point, an object in circular motion is travelling ________________.
But, as it travels circularly, _______________ changes continually. So, what must
exist? ____________________. Direction? __________________________________
12.Sometimes, it’s easy to see the _____________ directed force that causes an object to
move in a ________________. Other times, that force is harder to see.
Circular Motion
Inward Force
Twirl a toy plane over your head
Rotate in a carnival ride
Walk in a circle
13.The name of this ______________ directed force is ____________________________.
14.Whenever an object moves in a circle a ___________________ force exists. An object
CAN'T move in a ____________ without a ___________________ force. Without a
___________________ force, or if that force ends, an object will move ___________
____________________
15.Madge twirls a 0.2 kg toy airplane at the end of a 0.6 m string at a velocity of 7.5 m/s.
Fc? _____________
16.When he swings an 8 kg ball around his body in a circle on a rope, Max exerts a force
of 150 N to swing the ball at 4.5 m/s. How long is the rope? ________________
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Circular Motion Workshseets
17.Billy swings his 35 kg brother Mark in a circle around his body. The distance between
Billy and Mark's center of gravity is 0.7 m.
Describe the axis of rotation: ______________________________________________
Fc = ________________ Direction of Fc = ___________________________________
Is Fc a push or a pull? __________ Object exerting Fc: _________________________
18.While she is in this fun circus ride, Laura (55 kg) is spun in a circle at 15 m/s. She is
4.5 m from the middle of the hub at the center of the ride's wheel.
Describe the axis of rotation: ______________________________________________
Fc = ________________ Direction of Fc = ___________________________________
Is Fc a push or a pull? __________ Object exerting Fc: _________________________
19.An object sits untethered on the surface of a rotating table. When the table is spun
slowly, the object does not slide. Rather, it travels in a circular path.
Does a centripetal force exist? _______ If so, in what direction? __________________
If so, what supplies the centripetal force? _____________________________________
20.The formula for Centripetal Force (Fc) is ___________________ so Fc depends upon 3
things: ___________, ______________________ and _______________. What will
happen to an object moving in a circle if it is not possible to supply the needed Fc?
____________________________________________________________________
Provide an example: ____________________________________________________
Questions 21 - 23: An untethered 0.6 kg object sits upon the surface of a rotating
table 0.4 meters from the center of the table at 1.25 m/s. The coefficient of static
friction (s) between the object and the tabletop is 0.55.
20.What is the maximum centripetal force (Fc) that the tabletop can exert upon the object?
_________________
21.What centripetal force is required to keep the object travelling in a circle? __________
22.Can the static friction (fs) between the tabletop and the object provide the centripetal
force (Fc) required to move the object in this circle? ________. Will the object travel in
a circle or will it slide outwardly? ______________________________
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Circular Motion Workshseets
Physics, Mr. Kent
Class Work: Circular Motion #2
Name: ______________________________________
1. A ball is twirled in a circle at the end of a 0.75 m circle. It takes 1.05 s for the ball to
complete a single trip around the circle.
What is the radius of the motion? _________ Circumference? _____________
Linear velocity: _______________ rpm: ___________________
2. In circular motion, how does an object move over time? _______________________.
How does an object move at a particular time? ________________________________
______________________________________________________________________
3. What are the two names for the velocity of an object in circular moment at a particular
point? ____________________________ and _________________________________
4. Two objects sit on the surface of a rotating table top, Object #1 0.35 m from the center
of the table and Object #2 0.85 m from the center. The tabletop’s period (T) is 0.64 s.
rpmobject1 = __________ rpmobject2 = __________ Does radius affect rpm? ________
Linear velocity: Object #1: _____________ Object #2: _____________
Does radius affect linear velocity? _______________ How (explain)? _____________
______________________________________________________________________
______________________________________________________________________
5. At any point in time, an object in circular motion is traveling ________________. But
this direction keeps changing. Draw an object in circular motion to demonstrate this
change in direction. Show: Circle of motion, center of circle, the object at 3 different
positions, and arrows showing the direction of travel at those positions.
6. What is Newton’s First Law? ______________________________________________
7. Considering Newton’s First Law, what must exist to cause an object in circular motion
to change its direction continually? _________________. Its direction? ____________
8. What is the name of an inwardly directed force that causes an object to move in a
circle? _______________________________
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Circular Motion Workshseets
9. For each example of circular motion below, describe the centripetal force:
Circular Motion Example
Exerted By
Push/Pull
Ball twirled at the end of a string
A ball rolls around the outside of a
round room
A box on a revolving table top
A woman walks in a circle
Moon orbits the Earth
Questions 10 – 11: A 2.5 kg block of metal rests on a revolving platform 2.4 m from
the center (axis of rotation). The coefficient of static friction (s) between the block
and the surface of the platform is 0.1. You use a stopwatch to measure rotation speed
and you find that the platform rotates 15 times in 2 minutes.
10.rpm = __________ Circumference = _____________ Linear velocity = __________
Normal Force = _______________ Maximum Static Friction (fs) = _____________
Centripetal Force (Fc) required for the block to travel in a circle = _______________
Which is larger? Maximum fs or Fc required for circular motion? ________________
Will the block travel in a circle without sliding? ___________.
11.Let’s say the platform starts from rest (linear velocity = 0 m/s) and you gradually
increase its rotational speed. At some speed static friction will not be able to provide
the centripetal force required to keep the block from sliding. Below that linear velocity,
the block will travel in a circle. Above that linear velocity the block will slide toward
the outside of the platform. What is the maximum linear velocity at which the block
will travel in a circled without sliding? _____________ (clue: Set maximum fs = Fc).
12.Ball 1 (1.8 kg) and Ball 2 (2.2 kg) collide elastically. After the collision, both balls are
travelling East, Ball 1 at 3.5 m/s and Ball 2 at 1.75 m/s. Before the collision, Ball 2
was travelling East at 2.6 m/s. Velocity and direction of Ball 1 before the collision?
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Circular Motion Workshseets
Physics, Mr. Kent
Quiz: Circular Motion #2
Name: ______________________________________
Show work for partial credit!!!!!
Questions 1 & 2: An 8 kg box sits on a rotating surface 2.75 meters from the axis of
rotation. The coefficient of static friction (s) between the box and the surface is 0.45.
1. If the platform is rotated such that the linear velocity of the box if 3 m/s will the box
slip or travel in a circle?
FN = ________________
fs = ________________ Fc = ________________
Slip or travel in a circle? _______________
2. You want to rotate the surface as fast as you can without causing the box to slide. At
what linear velocity will the box start sliding? Linear velocity: ____________
Questions 3 – 6: Use your formula sheet (or your memory) to provide the following
formulas. DO NOT use another student’s formula sheet!!!
3. Formula for Kinetic Energy:
________________________
4. Formula for the following problem:
________________________
A dropped object falls 45 m to the ground. What is its speed just before hitting the
ground?
5. Formula for the following problem:
________________________
Liliana runs a 10 k race (10 kilometers) in 40 minutes. Average velocity?
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Circular Motion Workshseets
Physics, Mr. Kent
Daily Worksheet: Circular Motion #3
Name: ______________________________________
1. If an object is travelling in a circle there MUST be a ____________________________
causing that circular motion: NO __________________________.
2. Name the source of centripetal force (exerted by, push or pull):
a. Toy airplane twirled overhead: _____________________________________
b. The circus ride shown:
_____________________________________
c. A person walking in a circle:
_____________________________________
3. The amount of Centripetal Force (Fc) needed to cause an object to move in a circle
depends upon 3 factors:
Factor
Effect if increased
Increase Mass
Increase Linear (Tangential) velocity
Increase Radius
4. A 0.4 kg object sits 0.5 m from the center of a revolving surface. The coefficient of
static friction (μs) between the object and the surface is 0.65. What is the maximum
velocity at which the object can move linearly without slipping? In other words, what
is the maximum velocity at which the object will move in a circle? ______________
5. Draw two examples of force being applied to a wrench to cause circular motion: One a
Push and one a Pull. Show the wrench, a bolt, the circle, and the force in each diagram.
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Circular Motion Workshseets
6. Circular Force is its own quantity: ___________ (_____). Formula: ______________.
Force applied ___________________ to a rigid _______________ of length _______.
7. The SI-Unit of ________________ is the ______________.
8. Lisa exerts 40N of force to a 0.25 m wrench to turn a bolt. Torque? ___________
9. Lisa uses a 0.3 m wrench to exert 15 N-m of torque to turn a bolt. Force? __________
10.There are 2 ways to increase torque: Increase _________ and increase _____________
11.Lilly needs to turn a bolt that requires 6 N-m to turn. She tries to turn the bolt 3 times:



1st:
2nd:
3rd:
By exerting 20 N of force at the end of a 0.3 m wrench
By exerting 40 N of force at the end of a 0.15 m wrench
By exerting 12 N of force at the end of a 0.4 m wrench
Complete the following table to determine if Lilly be able to turn the bolt each time
Trial
Force
Lever
Arm (l)
Torque ()
Torque
needed
1st
6 N-m
2nd
6 N-m
3rd
6 N-m
Turn?
12.Which is easier for Lilly in the previous problem? The 1st or 2nd trial? _________
What does “easier” mean? ____________________________________________
The effect of increasing the Lever Arm: Less __________ needed, so _____________
13.Robert needs to turn a bolt that requires 90 N-m of torque to turn. How much force
must he exert if he:
a. Uses a 0.2 m wrench: ____________
b. Extends the wrench to a length of 1 m: ____________
14.The force of a torque _______ be supplied by an object’s _____________. For
example, a person can exert torque on a wrench by ___________________________.
15.A 60 kg woman tries to turn a rusted bolt with a 0.2 m wrench by standing on its end.
Force = ______________________ l = ___________  = ___________
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Circular Motion Workshseets
16.Label the following diagram of a see saw:
17.A see saw has _______ lever arms on either
side of a ________________ which provides
the _______________________________.
18.With a see saw, there’s an _____________ on either side. Each object exerts a
_____________ via its ________________ at a certain _________________ from the
_______________. The torque of each equals the product of its ______________ and
______________________________________________.
19.A 100 kg cricket player is on one side of a see saw 1.0 m from the fulcrum and an 80
kg cricket player is on the other side of the see saw 1.25 m away from the fulcrum. Is
the see saw in balance (not rotating)? _________
Player 1: mass = 100 kg
Force: ________ l = ________  = _____________
Player 2: mass = 80 kg
Force: ________ l = ________  = _____________
20.We’ll say that a see saw has a ________________ side and a ____________ side. If
there’s more torque on the right side, the see saw rotates ________________________.
If there’s more torque on the left side, the see saw rotates ________________________
Questions 21 & 22: Mary (40 kg) places her little brother Billy (20) in the right side
seat of a see saw 1.5 m from the fulcrum. She then sits on the left side of the see saw
1.0 m from the fulcrum.
21.Draw the see saw. Show Mary and Bill (including masses), length of lever arms. Draw
the see saw in balance even though, in the next problem, you may learn that it is not
balanced.
22.Mary:
m = ________ F = ________ l = ________ τ = ________
Billy:
m = ________ F = ________ l = ________ τ = ________
Balanced? _______ Direction of rotation: _______________________________
16
Circular Motion Workshseets
Physics, Mr. Kent
Class Work: Circular Motion #3
Name: ______________________________________
1. Mary decides to swing her 30 kg nephew around her body as fast as she can to make
him throw up. She swings him until his center of gravity is travelling 1.3 m from her
body at 4 m/s. How much force must Mary exert to swing her nephew? ____________
2. As he walks faster and faster around a circle of radius 2.5 m, John (75 kg) must push
outwardly harder and harder with his feet. The coefficient of static friction (s)
between the soles of his shoes and floor is 0.58.
John pushes out from the center of the circle. What provides centripetal force toward
the center of the circle to keep John moving in a circle? ________________________
What is the maximum speed that John can walk in a circle? _____________________
3. “Circular Force” has its own quantity. What it is? __________________ (______).
What is its formula? ______________________. It’s SI-Unit? _______________
4. The distance between O and A is 0.3 m and the distance between A and B is 0.35 m.
a. If a force of 25 N is exerted at point A, how much
torque is exerted on the bolt? ___________________
b. If a force of 25 N is exerted at point B, how much
torque is exerted on the bolt? ___________________
5. What are the two ways to increase torque?
a. __________________________________________________
b. __________________________________________________
6. Phil drives a nail through the very end of a meter stick in such a way that it can be
rotated along the surface of a table. He pushes at a point along the stick causing the
stick to rotate around the nail. He exerts 5.5 N of force and generates 2 N-m of torque.
How far from the nail did Phil push the meter stick? __________________
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Circular Motion Workshseets
7. Marsha (55 kg) is trying to loosen a very old and rusty bolt with a wrench. She doesn’t
know it, but the bolt will require 800 N-m of torque to turn. Marsha only has one
wrench, but she does have access to varying lengths of metal pipe that can be slipped
over the wrench’s handle to lengthen it. After a couple of futile attempts at pulling the
wrench with her arms, she decides to stand on the wrench/extension pipes. What force
will Marsha exert downward on a horizontal wrench/pipe? _________________
Complete this table which describes a few of Marsha’s attempts to loosen the bolt.
Wrench
Length
Force
Torque
needed
Torque ()
Turn?
0.5 m
0.75 m
1.0 m
1.5 m
8. Answer in physics terms: What is the advantage of using a longer lever arm when
exerting torque? (Don’t say “It makes things easier. Use a Physics quantity).
___________________________________________________________________
9. Linda is working in a cramped space where the most force she can exert on a wrench to
loosen a bolt is 25 N. She can, however, rig up a very long wrench handle using
extension pipes. How much must she extend a 0.15 m wrench to turn a bolt that
requires 275 N-m to loosen? (Careful: You’re asked for the extension length).
Extension length: _____________
10.Draw a see saw with an object on either side and label its parts: Fulcrum, lever arm 1,
lever arm 2 and axis of rotation.
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Circular Motion Workshseets
11.A 40 kg boy sits 1.5 m from the fulcrum on the right side of a see saw. His friend (30
kg) sits on the left side 2 meters from the fulcrum.
Boy:
Force on the see saw = ____________ l = ___________  = ___________
Friend: Force on the see saw = ____________ l = ___________  = ___________
Is the see saw balanced? _____________ Will it rotate? __________
12.Draw the face of a clock and then draw one arrow around the face’s outside labeled
“clockwise” and a second arrow labeled “counter clockwise”.
13.Draw pictures of 2 see saws. 1st picture (to the left): Draw a see saw that has rotated
clockwise until one end has hit the ground. 2nd picture (to the right): Draw a see saw
that has rotated counter clockwise until one end has hit the ground.
Questions 14 - 16: Describe the see saw. Provide the torque on the right, the torque
on the left and then after “Result” answer in one of 3 ways: “Balanced”, “Rotate
clockwise”. or “Rotate counter clockwise”.
14.A 45 kg object rests 1.2 m to the right of the fulcrum and a 50 kg object rests 1 m to the
left of the fulcrum.
Left side torque: __________ Right side torque: __________ Result: _____________
15.A 200 kg object rests 4.2 m to the right of the fulcrum and a 150 kg object rests 6 m to
the left of the fulcrum.
Left side torque: __________ Right side torque: __________ Result: _____________
16.A 60 kg object rests 2 m to the right of the fulcrum and an 80 kg object rests 1.5 m to
the left of the fulcrum.
Left side torque: __________ Right side torque: __________ Result: _____________
17.How far should a 45 kg child sit from the fulcrum on the right side of a see saw to
balance with a 25 kg child sitting 2.25 m from the fulcrum on the left side? _________
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Circular Motion Workshseets
Physics, Mr. Kent
Quiz: Circular Motion #3
Name: ______________________________________
*** Show work for partial credit ***
Questions 1 – 4: Use the following diagram to answer. A metal rod is anchored at its
bottom end in such a way that it can rotate around that point.
1. The magnitude of the torque directed to the right?
____________
2. The magnitude of the torque directed to the left?
____________
3. Net magnitude of the 2 torques _____________
4. Direction or rotation (clockwise/counter clockwise): _________________
5. An engineer is designing a spar that he will install at the top of a flat topped building
for use in lowering heavy furniture down to the window of an apartment below. The
spar will operate like the see saws we’ve seen in class. The edge of the building will be
the fulcrum. The spar will extend 10 m beyond the edge of the building and it will
extend 25 m back over the top of the building. The engineer plans to place a 500 kg
weight at the end of the spar on the rooftop. What is the maximum weight of furniture
that the spar can support? ______________ Maximum mass? _________________
6. A 2.8 kg object sits on a rotating table 0.6 m from its center. The coefficient of
static friction (µs) between the object and the table is 0.54. What is the maximum
velocity that the object can travel without slipping? _____________
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Circular Motion Workshseets
Physics, Mr. Kent
Daily Worksheet: Circular Motion #4
Name: ______________________________________
1. Circular force is called ______________. As with any circular motion, motion is
around an ______________________________. Between the axis and the circle is the
rigid _______________________. Torque is caused by a perpendicular ____________
exerted the length of the ______________________ from the ____________.
2. The formula for Torque is ____________________ and its SI-Unit is the __________.
3. There are 2 ways to increase torque:
a. ______________________________________________________
b. ______________________________________________________
Questions 4 & 5: Using a 0.35 m wrench, Jose needs a force of 25 N to turn a nut.
4. How much force must Jose exert if he uses a 0.25 m wrench on the nut? ____________
5. How much force must Jose exert if he uses a 0.7 m wrench on the nut? ____________
6. left = __________________________
right = __________________________
Balanced? __________
7. How far from the fulcrum must the smaller
person on this see saw stand for the seesaw to
be balanced? _________________
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Circular Motion Workshseets
8. For each row below, place the mass or masses with values for l on the see saw. Then
place one more mass at the position where the see saw is in balance. Record the l for
each placed mass then calculate the individual torques and get a total torque. Does the
total torque on the left each the total torque on the right?
Left Side
m1 l 1
1.5
τ1
m2 L 2
0.4
Right Side
τ2
τtot m1 l1
τ1
m2 L 2
τ2
τtot
.5
1.5
.25
.5
0.3
1
0.2
1.5
1
0.4
1.5
0.8
0.5
0.75
1
1
9.
m = ______________
10. l = ______________
11.A 35 kg giggling girl stands directly over the fulcrum of a see saw:
Mass: _______ Weight: _______ Lever Arm: _______ Torque: _______
12.We’ve seen 2 quantities that, if they were in ___________________ directions we
called one direction _________________, one direction __________________ and we
added them together to _________ them out. Those quantities were _______________
(______) and __________________ (_______).
13.The same goes for Torque. Let’s call __________________ torque _____________
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and ______________________________ torque negative. Draw a picture of a clock
with the arrows and signs for torque.
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Physics, Mr. Kent
Tougher Torque Problems
Name: ___________________________________
1. Draw all of the forces on the left and all of the torques on the right. Provide the sign of
each torque. Cross out any torques that you can ignore.
2. Draw all of the forces on the left and all of the torques on the right. Provide the sign of
each torque.
Plate and food: 0.3 kg
3. What is the direction of the force exerted by your thumb? _______________
4. Direction of the force exerted by your index finger? _____________
5. Where is the axis or rotation? __________________________
6. So, how much torque is exerted by your index finger? ____________
7. What force is exerted downward by the plate and food? ______________________
8. Where is that force exerted? _______________________________________
9. Draw all of the forces. Draw a dot to represent the axis of rotation. Label each force to
indicate the type of torque that generates (+, - or 0)
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10. Draw all of the forces. Draw a dot to represent
the axis of rotation.
11. Draw arcs to represent the torques. Label
each to indicate the type of torque (+, -, 0)
12. John holds a 0.3 kg plate that is 20
centimeters in diameter. Distances
form the left end of the plate:
 Thumb contact point:
2 cm
 Index finger contact point: 3.5 cm
Object
Index
Finger
Left Plate
Mass
N/A
Force
- Mashed Potatoes (0.15 kg)
- Steak (0.2 kg)
Lever Arm
Sign
6 cm
14 cm
Signed Torque
Right Plate
Mashed
Potatoes
Steak
Total
The plate is balanced. So how much torque must the thumb deliver? ____________ How
much force? ______________
Object
Thumb
Mass
N/A
Force
Lever Arm
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Sign
Signed Torque
Circular Motion Workshseets
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