Results

In this lesson you will learn about:

• Simple machines
• Be able to identify different kinds of machines
• Identify classes of levers and pulleys
• Determine mechanical advantage of a lever and pulleys
• Understand and determine the advantage of an inclined plane
• Describe and determine the advantage of a screw jack
• Describe and determine the advantage of a wheel and axel
• Describe and determine the advantage of a hydraulic press

What are simple machines? Simple machines are tools that make work easier. They have few or no moving parts. These machines use energy to do work with one movement. They make our work easier by letting us use less mechanical effort to move an object.

This section introduces you to the realm of physics, and discusses applications of physics in other disciplines of study. It also describes the methods by which science is done, and how scientists communicate their results to each other.

Physics is a branch of science. The word science comes from a Latin word that means having knowledge, and refers the knowledge of how the physical world operates, based on objective evidence determined through observation and experimentation. A key requirement of any scientific explanation of a natural phenomenon is that it must be testable; one must be able to devise and conduct an experimental investigation that either supports or refutes the explanation. It is important to note that some questions fall outside the realm of science precisely because they deal with phenomena that are not scientifically testable. This need for objective evidence helps define the investigative process scientists follow, which will be described later in this chapter.

Worked examples finding displacement and distance from position-time graphs.