C02 Dragster Unit
The ultimate objective of this unit is to use all the ideas and theory's of
physics taught up to this point in 8th grade to design the fastest balsa wood
dragster of the 8th grade class (materials are provided through the $10 Lab
Fee). Wind Tunnel Testing
Students will begin this unit by sketching out their dream car. They will have to think about what attribute is most important to them like being fast, roomy, long, light weight, or compact. Students will then use a wind tunnel to test the air flow resistance and drag of eight mock dragsters. They will record the mass of the car, a flow visualization sketch, and a verbal description. They will use this information to help them in designing their own car.
Isometric and Orthographic Drawings
Before constructing an object, an engineer must be able to visualize the object and draw a representation of how that object will look. One type a representation is an Isometric drawing-a representation on a flat surface of an object that is not flat. This is necessary to help students begin to think of their dragsters not as the 2-D paper they are drawing the design on, but the 3-D shape it will become. Another type of represention is an orthographic drawing. This type of drawing shows top, front, and right side views of a 3-D object. Again this is necessary in helping to visualize what students dragsters will look like once it is cut out of the block of wood.
Application and Review of Newton
Ramps and Friction 1st Law
We will start by discussing potential and kinetic energy, or stored and applied/moving energy. We will then review how friction can effect that energy. Students will use three different ramp surfaces: velvet, sandpaper, and smooth wood then record how each surface effects the amount of time for a match box car to travel down that surface in three trials. Students will then calculate the average speed for each surface.
Stomp Rockets 2nd Law
Students will use stomp rockets to test how force effects the distance the rocket travels and also as a review how mass effects distance traveled when the same amount of force is applied. Students will test this by adding marbles to the rocket and measuring the distance traveled by the rocket.
Alka-Seltzer Rockets 3rd Law
Students will learn about the chemistry taking place when water and an Alka-Seltzer tablet combine. They will then take that knowledge to develop a rocket with a film canister. They will develop a hypothesis, write a procedure, and record results with a conclusion.
