Section 2: The advantages machines provide can be calculated and compared. 

Key Ideas     Unit Checklist

  Unit D: Section 2 – Introduction


Figure D.S.2.1 – Ancient Egyptians used simple machines to build the pyramids.

Figure D.S.2.2 – Humans used to walk on treadwheel cranes to lift heavy stones.


Figure D.S.2.3 – Modern construction cranes only need one operator.
Construction Machines

For most of human history, people did not have large construction machines like we do today. Yet, ancient people were still able to build very large structures. The Great Pyramid of Giza in Egypt was built 4500 years ago, and is the same height as the tallest skyscraper in Edmonton. How did ancient Egyptians lift the heavy stones of the pyramid without cranes?

Ancient civilizations built structures by lifting stones with levers and hauling stones up ramps. These simple machines made doing work much easier, but still required many human workers to exert force. Romans eventually invented the treadwheel crane, which is like a human sized hamster wheel that lifts heavy objects. The treadwheel crane provided a greater mechanical advantage than levers and ramps.

Most modern construction machines contain giant levers connected to hydraulic systems that transfer force. These machines make it much easier and faster to move big loads. Gasoline and electricity have replaced human and animal power for machines. Modern construction machines have a huge mechanical advantage compared to ancient construction machines!

  Words to Think About:

Check out the word cloud below. It pictures the important words that you are going to learn in this section. Watch for these words, and combinations of these words, as you read. When you see them highlighted, you can click on them to learn more about what the word means. You can also visit the course glossary and read definitions for all of these words.

 
Lessons in This Section

Lesson D4: Working With Machines
Key Question – How does changing force and distance make doing work easier?
Lesson D5: Machine Efficiency
Key Question – Why do machines not work perfectly?
Lesson D6: Mechanical Advantage
Key Question – How do we calculate and compare the advantages that machines give us?
Lesson D7:  Applying Pressure
Key Question – How does pressure transfer force in hydraulic and pneumatic systems?
Lesson D8:  Hydraulic Systems
Key Question – Why do hydraulic systems provide a huge mechanical advantage for doing work?
Reading and Materials for This Section

Science in Action 8
Reading: Pages 278–303

Materials Lists for Unit:
Master List of all materials
Materials organized by lesson and activity

 Watch More

Building Structures with Machines

It took a lot of effort for ancient Egyptians to move stone blocks across sand, but they found a way to reduce friction and make the process more efficient. Watch this video to learn more.

 
 
 
 
This video explains how Egyptians used simple machines to build pyramids.

 
 
 
 
This video explains a theory of how Egyptians used spiral ramps to build pyramids.

 
 
 
 
Watch this video to see how a treadwheel crane lifts massive stone blocks.

 
 
 
 
This video shows some models of different construction crane inventions.