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Supersonic Spies

Classroom Activity

Objective
To interpret incomplete information to build a simple wheel-and-axle machine.

• copy of student handouts
  Race to Be First (PDF or HTML)
  Welcome to Spin City Inc. Web Site! ( HTML)

• copy of "Materials for each team" Teacher Instructions ( HTML)
  

1. Western engineers nicknamed the Soviet TU-144 "Konkordski" because of its remarkable similarities to France's Concorde. But it wasn't an exact replica. While both sides "borrowed" ideas from each other, different measurement systems and hardware, as well as missing information, made interpreting designs difficult. Students can try interpreting information to build a simple wheel-and-axle machine that lifts a paper cup in this activity.

2. Divide students into teams and distribute copies of the "Race to Be First" and "Welcome to Spin City Inc. Web Site!" student handouts.

3. Prepare a set of materials for each team and place each team's materials in a large box.

4. Tell students their challenge is to build a working model of the machine using the information and selecting from the materials provided. Refer to Machine Assembly Instructions in Activity Answer below for directions to guide students who encounter difficulties. Compare students' completed machines and discuss how teams interpreted the information. How does this activity provide insight into how the TU-144 was similar to but not exactly like the Concorde?

Part of what students are doing in this activity is reverse engineering, where students look at something that exists to figure out how it works rather than building from the ground up. From each piece of information in Part I, students can interpret different clues about the design and assembly of the Puff Machine. Figure A is the pattern for the pinwheel. Students should begin by enlarging the pinwheel based on the scale of 0.5 cm = 1 cm. The solid lines indicate where to cut the piece of paper and the dotted lines indicate where to fold. The circles indicate where to punch holes. Figure B shows how the corners of the pinwheel are folded and attached to the straw and how the rubber bands can be used to keep the pinwheel in place. It also shows how to hold the machine so that the straw spins freely as the pinwheel turns. Figure C shows the cup and string attachment. Students will interpret through trial and error how the string is attached to the straw. Because there is no exact description of materials, student choices may vary. For example, one team may choose regular bond paper for the pinwheel while another may choose a card stock. This provides a good opportunity to discuss how different materials behaved within the design and why.

Students familiar with pinwheels will be able to recognize that blowing on the pinwheel will cause it to turn. If students are familiar with wheel-and-axle machines, they may also use this information to help them understand how the machine works. If students are not familiar with this simple machine, you may want to identify it at the activity's end.

In Part II, students may experiment by changing such things as the size of the pinwheel, the type of paper used for the pinwheel, the diameter of the straw, or even substituting entirely new materials.

Machine Assembly Instructions

Materials:

• pattern (Figure A) from Welcome to the Spin Inc. Web Site!
• 22 cm by 28 cm (8-1/2 in. by 11 in.) sheet of paper
• 2 rubber bands
• 51 cm (20 in.) piece of string
• small paper cup
• pencil
• scissors
• straw

1. Using the pattern (Figure A) and scale provided on the "Welcome to the Spin Inc. Web Site!" student handout, draw a full-size pattern on a sheet of paper; full size will be 10 cm by 10 cm (4 in. by 4 in.). Transfer all of the pattern's lines and circles.

2. Use a pencil to punch a hole through the center circle. Then punch a hole in each corner circle.

3. Cut along the solid lines, making sure not to cut the center hole.

   

4. Insert a straw through the center hole.

5. Fold each corner along the dotted line and insert the straw through each corner hole. Slide the pinwheel to the center of the straw.

   

6. Wrap a rubber band around the straw on each side of the pinwheel to keep the pinwheel in place.

7. Punch two holes on either side of a small paper cup. Thread one end of the string through two holes in the paper cup and tie it to the middle of the string. Tie the other end of the string to one end of the straw.

   

8. Hold the straw with both hands as shown. Blow on the pinwheel. As the pinwheel turns, the straw rotates, winding the string and lifting the cup.