Inclined Planes, Wedges and Screws – Lesson Summary

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Learning Objective

In this lesson we will learn how inclined planes, wedges and screws provide mechanical advantage.

Learning Outcomes

By the end of this lesson you will be able to:

  • Explain what an inclined plane is and describe how it provides mechanical advantage.
  • Explain what a wedge is and describe how it provides mechanical advantage.
  • Explain what a screw is and describe how it provides mechanical advantage.
  • Give examples of inclined planes, wedges and screws.
  • Calculate the mechanical advantage of inclined planes, wedges and screws.
  • Compare the mechanical advantage provided by different inclined planes, wedges and screws.

 
inclined planes wedges and screws lesson contents

(Image: Calibrys, Adobe Stock)

Lesson Topics

1 | Inclined Planes as Simple Machines

2 | Mechanical Advantage of Inclined Planes

3 | Wedges and Screws

4 | Wedges as Simple Machines

5 | Mechanical Advantage of Wedges

6 | Screws as Simple Machines

7 | Mechanical Advantage of Screws

8 | Summary

Lesson Summary

  • An inclined plane (ramp) is a flat, tilted surface, supported at each end.
  • Inclined planes increase and change the direction of forces to increase the vertical position (height) of objects.
  • They do this by counteracting the gravitational force (weight) of the objects.
  • The mechanical advantage of an inclined plane is given by the formula:
  • mechanical advantage formula inclined plane summary
  • A flatter inclined plane will have a greater mechanical advantage and therefore require less effort, but a longer length.
  • A steeper inclined plane will have a smaller mechanical advantage and therefore require more effort, but a shorter length.
  • The mechanical advantage of an inclined plane is also given by the formula:
  • mechanical advantage formula force summary
  • Wedges and screws can be considered as derivations of inclined planes.
  • A wedge is two inclined planes joined at the base.
  • A screw is an inclined plane wrapped around a cylinder.
  • Like inclined planes, wedges and screws increase and change the direction of forces.
  • They are used for separating objects, moving objects, or holding objects in place.
  • The mechanical advantage of a wedge is given by the formula:
  • mechanical advantage formula wedge summary
  • A longer, thinner wedge will have a greater mechanical advantage and therefore require less effort.
  • A shorter, thicker wedge will have a smaller mechanical advantage and therefore require more effort.
  • The mechanical advantage of a screw is given by the formula:
  • mechanical advantage formula screw summary
  • The pitch of a screw is the distance between the threads.
  • A screw with a larger head and a smaller pitch will have a greater mechanical advantage and therefore require less effort, but more turns.
  • A screw with a smaller head and a larger pitch will have a smaller mechanical advantage and therefore require more effort, but less turns.

 
pile of screws

(Image: julien leiv, Adobe Stock)

(Header image: max blain, Adobe Stock)