Introduce the lesson by gathering a deep breath and blowing it out. Then, ask the students to draw a picture of what they see in their science journals (expect some confused looks). Gather another deep breath, this time blowing it out onto a pinwheel and ask the students to draw a picture of what they see in their science journals. Give the students a few minutes to create their drawings. Ask the students, "What was the difference in the two drawings"? Facilitate a discussion about the power of wind (although it is invisible, it is very powerful), and then pose the question, "What could happen if someone could harness the wind?"
Read the picture book The Boy Who Harnessed the Wind, by William Kamkwamba and Bryan Mealer, aloud to the students. After reading, talk about what it means to "harness the wind".
Pass out the Wind Rating Chart (see attachment), and place the students in groups with 4 students in each group. Using the Wind Rating Charts, the students will test different materials to investigate their ability to "harness" the wind and use the Wind Rating Chart to rate their ability.
After groups have had some time to explore the materials, ask the following:
1. Do you notice any similarities about the materials that easily harness the wind? (they were thinner, lighter, easily allowed air to travel)
2. Which material/materials worked best at harnessing the wind? (plastic grocery bags, clear plastic wrap, paper)
Pass out the Puff Mobile Design & Evaluation Sheet (see attachments) and say, "Remember that puff of air that made the pinwheel spin? You are going to design a vehicle that is powered by a puff of air." Allow the groups time to design, build, and test their puff mobiles. Then section off a track and allow the groups to race their puff mobiles.
Create a class chart on the wall or smartboard to record data from the race, including which puff mobile traveled the farthest in the shortest amount of time. Next to that chart, create a Wind Facts Chart to compare design features of each puff mobile. Lead a discussion about the similarities or differences in the vehicles that traveled the farthest distance in the shortest amount of time. What features do they have in common that may have helped to increase their time?