Making Machines with Wheels and Axles

How do wheels and axles work together?
What is the relationship between wheels, friction and motion?
What are gear wheels?
Making Machines with Wheels and Axles looks at everything from historical examples of this simple machine, such as a pottery wheel, to the role of pulleys in more complex machines, such as gearboxes.
This series explains the physics behind simple machines using everyday examples and asks readers to embark on practical projects to show this science in action.