Harnessing the Wind (Part Two)

Learning Resource Type

Lesson Plan

Subject Area

Science

Grade(s)

Overview

In this lesson, students will investigate the design behind William Kamkwamba's windmill. Using his design ideas, students will design, construct, and test their own windmill.

This lesson results from a collaboration between the Alabama State Department of Education and ASTA.

Science (2015) Grade(s): 4

SC15.4.4
Design, construct, and test a device that changes energy from one form to another (e.g., electric circuits converting electrical energy into motion, light, or sound energy; a passive solar heater converting light energy into heat energy).*

Vocabulary

criteria
constraint
energy
device
convert
design
construct
kinetic
potential
transform
evidence
engineering design process
ask
imagine
plan
create
improve

Knowledge

Students know:

Energy can be transferred from place to place by electric currents.

Skills

Students are able to:

Use scientific knowledge to generate design solutions that convert energy from one form to another.
Describe the given criteria and constraints of the design, which include the following:

The initial and final forms of energy.
Describe how the solution functions to transfer energy from one form to another.

Evaluate potential solutions in terms of the desired features.
Modify the design solutions to make them more effective.

Understanding

Students understand that:

Energy can be transferred in various ways and between objects.
Engineers improve existing technologies or develop new ones but are limited by available resources.

Scientific and Engineering Practices

Constructing Explanations and Designing Solutions

Crosscutting Concepts

Energy and Matter

Primary Learning Objectives

After completing this activity, students should be able to do the following:

1) identify key features in William Kamkwamba's windmill design

2) design, construct, and build their own device that changes wind energy to mechanical energy

Procedures/Activities

Engage:

Introduce the lesson by holding up the pinwheel from the previous day's lesson and asking the following questions:

Can something as simple as a pinwheel do work?

What changes can be made to a pinwheel to make it do work for us?

Allow the students a few minutes to discuss some ideas.

Ask the students if they remember the boy from yesterday's story, The Boy Who Harnessed the Wind? Allow the students a few minutes to review the story. "Today, I will show you a video of the man from the story, William Kamkwamba who built the windmill and managed to harness the wind to bring water to his village."

Show the video.

Explore:

Show the students a diagram of William KamKwamba's windmill design and tell them they are going to investigate the design behind his windmill.

Place the students in groups of 4 students per group and give each group a copy of William Kamkwamba's windmill design and a crank flashlight. Each group will also be given a dynamo torch lab sheet. Give the students time to explore the flashlight and complete the lab sheet, then ask the following question:

What makes the flashlight work?

Did you find any similarities between the flashlight I gave you and William's design?

Lead a discussion about any similarities they may have found (the turning of the crank caused the flashlight to power on - William used a bicycle dynamo in his windmill design to achieve the same results).

Ask the students what they noticed when they changed the speed of the crank (when they turned the crank faster, the light came on and was brighter - when they turned the crank slower, the light didn't come on or was much dimmer).

Draw students' attention to the statement, on the design sheet, William makes about modifying his design and increasing the number of blades from 3 to 4 in order to provide more power output and ask:

Why do you think he decided to do that? (because 4 blades gave him more wind power and more electricity just like cranking the flashlight faster made the light brighter).

Discuss with the students that instead of using his hand, William used the power of the wind to turn his dynamo to bring electricity to his village.

Explain:

Tell the students "Now it is your turn to design and construct your own windmill." Working cooperatively in groups, students will design and construct a working windmill that will lift at least 5 coins up in a cup. Pass out the Windmill Design and Evaluation Sheet and have students brainstorm a design within their group. They will test their working windmill and record their data.

How many coins did their windmill lift?

What changes could they make to improve the amount of coins their windmill can lift?

Elaborate:

To help wrap up this lesson, have students brainstorm together with their group to complete the Windmills at Work graphic organizer and discuss other ways windmills can be used to make work easier for people.

Assessment Strategies

This lesson will be assessed based on the rubric for the Windmill, the Design and Evaluation Sheet, and the Dynamo Torch Lab Sheet.

Acceleration

As an extension, students can research the history of windmills and create a timeline on posterboard to display in the classroom. Students should be sure their timeline addresses the following questions:

When was the first windmill used?

What was it used for?

Are windmills still in use today?

How has their design changed over the years?

Intervention

The teacher may need to reteach the concept to struggling students. Students who need extra support may also need to be placed in a group with students who are sensitive to the needs of that student.

Total Duration

31 to 60 Minutes

Background/Preparation

For Teacher: The teacher must be knowledgeable about the following:

At the age of 14, William Kamkwamba built his villiage a windmill out of scrap materials. He used his windmill to bring much needed electricity to his village. Windmills are considered a type of engine. They use the power of wind to make energy. Wind turbines are a more modern way of converting the power of wind to electricity.

Crank flashlights are flashlights that work when you turn a crank with your hand. These are used primarily during emergencies and during the war when batteries or electricity is not easily accessible. Crank flashlights get their electricity from a generator called a dynamo that is activated when the crank is turned. William Kamkwamba also used a Dynamo in his windmill and used the power of the wind to turn the crank.

Teachers should always be alert to safety in the science classroom. Please review safety guidelines with students before daily instruction. Students should wear safety goggles when working with small parts with a potential to fly up into a student's eye.

For students: The students should be knowledgeable about the following:

The wind has power that can be harnessed by certain materials. William Kamkwamba was able to harness the wind to design a windmill and bring electricity to his village.

Materials and Resources

a toy pinwheel

crank flashlight (one per group)

coins

a small fan or hair dryer to provide the wind power

Per windmill:
tape,
paper, cardstock, or index cards for the blades,
pencil or single hole punch,
2 rubber bands,
scissors,
straw, small paper cup, piece of string, 20 in. (51 cm)

For download:
copy of William Kamkwamba's design

dynamo torch lab sheet

directions for windmill

Windmills at Work Graphic Organizer

rubric for windmill design

Windmill Design and Evaluation Sheet