Inclined Planes and Pulleys
Force, Motion, and Energy
Inclined Planes and Pulleys
Background
1.  What does a simple machine do?
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2.  What unit are forces measured in? ________________________________________________
3.  Describe an inclined plane.
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4.  Name at least two examples of inclined planes.
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5.  Describe a pulley.
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6.  What are the two types of pulleys?
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7.  What are two locations would you expect to see a pulley?
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Inclined Planes and Pulleys
Force, Motion, and Energy
Part I: Using an Inclined Plane
1.  Force required in N, to move the bag of sand straight up to a height of 10 cm: _____________
2. Inclined Plane Data Table
Distance traveled by
the Load (cm)
(Length of Inclined Plane)
Force Required to Move the
Load to a Height of 10 cm
using the Inclined Plane (N)
Angle of Inclined Plane
(degrees)
2.  Create two graphs from your data table. Title each graph.
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
.5
0
0
5
10
15
20
25
Angle of Inclined Plane (degrees)
Title: __________________________
Force (N)
Force (N)
Title: __________________________
30
5.0 4.5
4.0
3.5
3.0
2.5
2.0 1.5 1.0 .5 0 0
10
20
30
40
50
Distance (cm)
60
4.  What conclusion can you draw from these two graphs?
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Inclined Planes and Pulleys
Force, Motion, and Energy
Part I: Using an Inclined Plane, continued
5.  Draw a diagram of the inclined planes that you constructed. Label the length of the inclined
plane and the corresponding angle of each set up.
6.  How did the use of the inclined plane affect the amount of force needed to raise the load 10 cm
above the tabletop?
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7.  Describe the relationship between the length of the inclined plane and the amount of force
needed to raise the load 10 cm above the tabletop.
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8.  Describe the relationship between the angle of the inclined plane and the amount of force
needed to raise the load 10 cm above the tabletop.
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Part II: Using a Pulley
1. Force required in N, to lift the bag of sand straight up to a height of 10 cm: _________________
2. Pulley Data Table
Type of Pulley
Force required to Lift the Load
10 cm Using the Pulley (N)
Fixed
Movable
2 Pulley System
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Inclined Planes and Pulleys
Force, Motion, and Energy
Part II: Using a Pulley, continued
3.  In the spaces below, draw and label a diagram of each pulley system you assembled and used
in the activity. Count the number of supporting strings and label each of your diagrams with the
number of supporting strings.
Fixed
Movable
2 Pulley System
4.  Compare the amount of force needed to lift the load with one fixed pulley to the amount of force
needed to lift the load using the moveable pulley.
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5.  Compare the amount of force needed to lift the load with one fixed pulley to the amount of force
needed to lift the load using the 2 pulley system.
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6.  What happened to the force required to lift the load as more supporting strings were added to
the system?
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7.  Why would it be helpful to use a fixed pulley if it doesn’t reduce the amount of force?
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8.  Why would one elevator need many pulleys to operate?
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Inclined Planes and Pulleys
Force, Motion, and Energy
Reflections and Conclusions
1.  What does a simple machine do?
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2.  How does an inclined plane decrease the amount of force needed to move an object?
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3.  How does a pulley decrease the amount of force needed to move an object?
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4.  Is there a connection between the distance the load travels and the change in force required to
move a load when using an inclined plane or a pulley? How could you test this question?
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