<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
You are viewing an older version of this Concept. Go to the latest version.

# Wheel and Axle

## One of six types of simple machines. Consists of two connected rings or cylinders, one inside the other.

Estimated3 minsto complete
%
Progress
Practice Wheel and Axle

MEMORY METER
This indicates how strong in your memory this concept is
Progress
Estimated3 minsto complete
%
The Amazing Wheel

### The Amazing Wheel

Credit: Carlo Lasinio (Engraver), Giuseppe Angelelli , Salvador Cherubini, Gaetano Rosellini (Artists), Ippolito Rosellini (Author)
Source: http://commons.wikimedia.org/wiki/File:Egyptian_Chariot_(colour).jpg

This colorful image shows an ancient Egyptian chariot. The chariot was a two-wheeled vehicle pulled by a horse. The wheel was invented thousands of years ago, probably more than once. It’s been called one of the most important inventions of all time. Do you know why?

#### The Back Story

• A wheel actually consists of two concentric wheels, one inside the other. The inner wheel is called the axle, and the outer wheel is called the wheel.
• You might think that the wheel was invented for transportation, but the earliest wheels were probably used for other purposes.
• Credit: Emran Kassim
Source: http://www.flickr.com/photos/emrank/3142426851/

Modern wheels are also used for purposes other than transportation [Figure2]

#### What Do You Think?

At the links below, further explore the wheel and its history. Then answer the questions that follow.

1. Describe a wheel and axle. What is the general purpose of a wheel and axle?
2. The earliest known wheel and axle wasn’t used for transport. When, where, and how was it used?
3. When and where was the wheel and axle first used for transport?
4. Explain how a wheel and axle can increase either force or the distance over which force is applied.
5. List some of the many uses of the wheel and axle.
6. What do you think? Do you consider the wheel and axle to be one of the most important inventions of all time? Why or why not?

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes

1. [1]^ Credit: Carlo Lasinio (Engraver), Giuseppe Angelelli , Salvador Cherubini, Gaetano Rosellini (Artists), Ippolito Rosellini (Author); Source: http://commons.wikimedia.org/wiki/File:Egyptian_Chariot_(colour).jpg; License: CC BY-NC 3.0
2. [2]^ Credit: Emran Kassim; Source: http://www.flickr.com/photos/emrank/3142426851/; License: CC BY-NC 3.0

### Explore More

Sign in to explore more, including practice questions and solutions for History of Science.