Work, Motion, and Forces

Chapter 5

Pushing a car that is stuck or is broken down may look like hard work. But, in the physical world, no work occurs unless the car moves. Work occurs when a force is applied to move an object over a distance. Understanding the physics behind motion, force, and work can help you to better understand how people and machines do work.

Goal Setting

You use simple machines at home and at work every day. A knife, a screwdriver, and a pair of scissors are all examples of simple machines. Even the system set up to easily lift a garage door is a simple machine. Most things that help to make a task easier can be thought of as simple machines. Think of a task that you often do at home or at work that is difficult to perform and think of ways you can use a simple machine to make this task easier. Write down your ideas. After you have read this chapter, draw a sketch of a simple machine that might help with your task and explain how it will make the task easier.