Air Is Matter
(Image)
Exploring Windmill Design
(Video)
What Is the Design Process?
(Video)
Windmill Gallery
(Image)
For hundreds of years, people have harnessed moving air (wind) to do work. The earliest forms of wind-powered machines were sailboats. Wind pushing against the sails of a boat provided the energy to move the boat across the water, saving people the trouble of rowing. Later, people discovered that if they attached sail-like panels to a wheel at the top of a stationary tower, wind blowing against the panels would cause the wheel and the central shaft to which it was attached to turn. The shaft drove mechanisms inside the tower that were used to mill, or grind, grain into flour. These wind-driven mills were called, simply, windmills. And even though wind-driven machines are now also used to pump water from wells and to generate electricity, the name windmill has stuck.
In this activity, students review the engineering design process and discuss how wind can be used to help get work done. They look at a variety of windmills, focusing on the different materials used in the construction of windmills and the type of work each windmill is designed to do. Finally, they use simple materials to build their own windmills to do work.
1. Tell students that they will use the engineering design process to explore windmills. Lead a discussion about windmills to find out what students already know. Ask:
Note that correct answers are not required here; you are simply looking for a base level of understanding to start the activity.
2. Ask students to describe how windmills do work. (They convert wind energy to mechanical energy.) Brainstorm together to come up with a good description (e.g., converting wind energy into work to help people).
3. Lead a conversation about the engineering design process to find out what students already know. Show the video What Is the Design Process? and review the description that the class came up with in step 2. Ask:
As students go through the various steps of the design process, you may want to record the steps in a chart. This will give students an overview of the process and where they are in it.
4. Tell students that they are now starting the brainstorming and research component of the design process. Have them view the Air Is Matter still collage, and encourage them to discuss the types of things that air can do. Ask:
5. Start by reviewing the design challenge that students came up with in steps 2 and 3 [to design a machine (windmill) that uses energy from the wind to do work].
6. Next, show students the Exploring Windmill Design video. Ask:
7. Windmills have changed dramatically since their invention. Have students review the Windmill Gallery still collage and look for the following design features:
8. Lead a discussion based on their observations.
9. Pass out to each student a copy of the Windmill Worksheet (PDF), the two different-sized patterns featured in the Windmill Template (PDF), and the materials needed to construct their own windmill. Let students choose the pattern size they want to use. Encourage the class to use a variety of sizes.
10. After the windmills are complete, have students test them to see if they accomplish the work of lifting the cup. After several minutes, ask:
11. Lead a discussion about what design changes they would make if time allowed them to build another windmill. Ask:
Discuss the following: