Just Plane Simple
Figure 1. A wheelchair ramp or an inclined plane?Copyright U.S. Department of Justice, Civil Right Division, http://www.usdoj.gov/crt/ada/votingchecklist.htm.
This lesson introduces students to three of the six simple machines used by many engineers. These machines include the inclined plane, the wedge and the screw. In general, engineers use the inclined plane to lift heavy loads, the wedge to cut materials apart, and the screw to convert rotational motion into linear movement. Furthermore, the mechanical advantage describes how easily each machine can do work and is determined by its physical dimensions.
Simple machines are extremely valuable to engineers since they are used to accomplish extraordinary amounts of work with ease. In particular, engineers can design a simple machine which provides a desired mechanical advantage so that work can be done efficiently and effectively. The inclined plane, wedge and screw are used in many engineering systems today, including stairs, can openers, and airplanes, among many others.
After this lesson, students should be able to:
- Explain how the inclined plane, wedge and screw make work easier.
- Identify how the inclined plane, wedge and screw are used in many familiar engineering systems today.
- Discuss the mechanical advantage of an inclined plane, wedge and screw.