# Connexions

You are here: Home » Content » An Introduction to Mechanical Engineering for High School Students » Torque

### Recently Viewed

This feature requires Javascript to be enabled.

Inside Collection (Course):

Course by: Melissa Fernandez. E-mail the author

# Torque

Module by: Jim Young. E-mail the author

Summary: Describes basic concept of torque. Understanding torque is key to understanding the building blocks of more complex machines, like robots.

A torque is a force applied at a distance from a pivot point, such as an axle or shaft. When describing torques, one must include the magnitude and direction of the force, plus the perpendicular distance from the pivot where the force is applied. The magnitude of the torque is the product of the force and the distance from the pivot. Since torque is a product of force and distance, one may be "traded" for the other. The same torque can be created by applying a different force at a different distance from the pivot.

Figure 1 shows a beam, such as a LEGO beam, with an axle pivot at one end, the fulcrum. The beam is free to rotate about the fulcrum, so a downward force will cause the beam to rotate downward, or clockwise, in Figure 1. The force of 8 units shown applied at a distance of 8 units from the fulcurm produces a downward, or clockwise, torque of 64 units.

If we want the beam to remain stationary, we must apply an equal torque in the upward direction. We can apply force at many points along the beam, but the force needed depends on where we apply it because of the force-distance trade-off of torque. We could apply an upward force at the same place as the downward force, having the same magnitude. Or, as shown, we could apply a smaller force, 4 units, at a larger distance, 16 units. The smaller force at a larger distance produces the same torque, 64 units. By the same reasoning, we would have to apply a larger force closer to the pivot to produce the same upward torque.

Figure 1 illustrates how a simple lever works and why it is useful. Applying a small force at a large distance from the pivot can produce or oppose a very large force close to the pivot. "Give me a long enough lever, and I can move the world."

In summary, torque is a force applied at a distance from a pivot. When describing torques, one must include magnitude, direction, and perpendicular distance from the pivot. Since torque is a product of force and distance, one may be "traded" for the other. The concept of trading distance traveled/applied for force experienced/applied is key to many simple machines.

## Content actions

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

#### Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

#### Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks