Wind Tube Category: Physics Type: Make and Take Materials: 1 1 1 Large piece of wood (8”x 8”) Medium piece of wood Long clear plastic tube (makeable with transparent paper and tape) 4 Wooden legs 1 Motor 1 Plastic propeller, or plastic bottle and glue stick to make propeller 2 9V batteries, or whatever batteries you need to make you’re motor run well 2 9V battery snaps 2 9V battery holders (optional) 1 Switch (optional) 1 Small plastic tube or canister (optional) Electrical Wire 1 Roll of duct tape Piece of cardboard 1 Screen with fairly large holes Equipment: Glue Gun Wood Planer Chisel Saw Ruler Pencil Sandpaper T-­‐square (optional) Hole saw Vice or clamp Hammer Nail Hand saw © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. Video: http://youtu.be/GojphsAxjjY How To: Measure and cut an 8” x 8” piece of wood. A T-­‐square can be used to help make straight lines. Secure the wood in a vice or clamp. Smooth all of the edges on the board using a wood planer. Sand the edges to create a smooth finish. Cut a square piece of wood just slightly smaller than the tube. Drill a hole in the center big enough for the motor to sit in. Sand the edges. Place the square in a vice. Using a hammer and a nail, cut a notch wide enough to hold six wires in Attach battery snaps to the two 9V batteries. Tie one red and one black wire together and © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. the side of the wood. wrap electrical tape around the connection. Connect the remaining red wire to the motor. Attach two pieces of electrical wire to the switch. Connect one to the motor and the other to a 9V battery. Place the motor in the center of the small board and run the wires through the gap in the board. Glue the board onto the baseboard. Glue 9V battery holders onto one side of the baseboard and place the batteries in them. You can also use rubber bands or glue to make the attachment. © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. Measure the length of the switch and its wires, cut a small plastic tube or cannister the same length. Drill a hole for the switch to poke through one end. If necessary glue the switch into place. Glue the switch and its holder to the baseboard. (Instead of using a switch two wires can be twisted and untwisted to act as a switch.) Push the wires flush against the board and glue into place. To avoid melting the plastic coating on the wires, place the glue on the board and then push the wires into it. Glue the motor in place without getting glue inside it. Be sure the shaft is not dragging on the baseboard. A complete baseboard should look something like this. Measure four legs for the tube, approximately 1.5” wide by 3.5” tall. © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. Cut the legs. Glue one leg in the middle of each side of the wooden square. Wrap a strip of cardboard around the top of the plastic tube and tape closed. Wrap duct tape around the cardboard to strengthen it. Place the cardboard circle on mesh wire. Use wire cutters to cut a square piece slightly bigger than the circle. Slide the cardboard onto the tube. Line up the edges of the the tube and cardboard. Place the mesh wire on top of the tube and fold down the edges. © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. Tape the wire to the cardboard tube. Now you can slide the mesh off and on to put different things into the tube. Place hot glue around the bottom of the tube and press it onto a square piece of mesh. Cut any excess wire after the glue has dried. Hot glue the tube to the four wooden legs as well as any sharp pieces of wire that may be sticking out. If you don’t have a propeller, make one using a plastic bottle and a glue stick. Push the propeller onto the motor. Drop different things into the tube (scrunched up paper and balls), turn it on and watch what happens. © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. Fine Points: The measurements given for the wood depend on the size of the large clear plastic tube. The wire connections can be soldered instead of using electrical tape. If the hole for the motor is too big, place pieces of cork into the hole to keep it upright and secure. Other items to float in the tube include cardboard tubes and practice golf balls. You can even build new objects and see how they float. → The top screen may be removed to explore the air’s motion as it emerges from the top of the tube. Concepts Involved: • Air can be used to lift things. • In stable flight, upward force (lift) and downward force (weight) must balance perfectly. →
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Can you see, hear, feel or smell air? What sorts of things can air move? What are examples of things that can fly? Which of the examples that you named above, occur naturally and which are man-­‐made? What forces must be overcome to fly? What do you think is the key to making something fly in the tube? Elaboration: Wind tubes allow us to explore, experiment and play with moving air. The wind tubes in this project are stripped down versions of wind tunnels, which are used to test factors like airflow, drag, turbulence, and air resistance on aircraft parts, like wings and propellers. Even though we can’t see it air, is all around us and is pushing on everything including us, we don’t notice this because our bodies are pushing it back! This is called atmospheric pressure. Air can be gentle and pleasant but with speed it will gain energy and force and can be used to lift things. The wind tube can help us to understand how things that are heavier-­‐than-­‐air can fly. To float in place, an object’s weight must not be greater than the upwards force due to wind. If an object’s weight is lighter than the upward force, it will fly out of the top of the tube. This is a simplified version of the give-­‐and-­‐
take problem that all aeronautical engineers must surmount when building a flying machine. In stable flight, upward force (lift) and downward force (weight) must balance perfectly. If one is greater, the aircraft will soon be accelerating either up or down. This is Newton’s second law, often expressed as F = ma. In our wind tube, the upward force comes straight from the wind on the object. Airplanes get this force by air moving over the top of their wings and creating lift by lowering the pressure on top. Links to k-­‐12 CA Content Standards: Grades k-­‐8 Standard Set Investigation and Experimentation: Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other strands, students should develop their own questions and perform investigations. Grades k-­‐12 Mathematical Reasoning: 1.0 Students make decisions about how to approach problems: 1.1 Analyze problems by identifying relationships, distinguishing relevant from irrelevant information, sequencing and prioritizing information, and observing patterns. © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included. 1.2 Determine when and how to break a problem into simpler parts. 2.0 Students use strategies, skills, and concepts in finding solutions: 1.1 Use estimation to verify the reasonableness of calculated results. 1.2 2.2 Apply strategies and results from simpler problems to more complex problems. 1.3 Use a variety of methods, such as words, numbers, symbols, charts, graphs, tables, diagrams, and models, to explain mathematical reasoning. 2.5 Indicate the relative advantages of exact and approximate solutions to problems and give answers to a specified degree of accuracy. 3.0 Students move beyond a particular problem by generalizing to other situations: 3.1 Evaluate the reasonableness of the solution in the context of the original situation. 3.2 Note the method of deriving the solution and demonstrate a conceptual understanding of the derivation by solving similar problems. 3.3 Develop generalizations of the results obtained and apply them in other circumstances. © 2013 Fresno Community Science Workshop. All Rights Reserved worldwide. When linking to or using FCSW content, images, or videos, credit MUST be included.