Unit Concepts

Energy, which is the ability to cause change, can be transferred and can change form.

• There are many different forms of energy;energy can be transferred.
• Energy can be changed, or transformed, from one form to another.
• Energy is needed to do work, which is done when a force moves through a distance.

Simple machines, which can be classified into a few basic types, make work easier.

• Simple machines make work easier by increasing the effect of a force or by changing the direction of a force; ramps are an example of an inclined plane, a type of simple machine.
• Levers and pulleys are types of simple machines that can be set up in a variety of ways for maximum effectiveness.
• A wheel and axle is a simple machine made up of two connected wheels of different sizes that turn about the same point.

Chapter 1  Energy and Work

Chapter 2  Work and Machines