C02
Dragster Unit
The ultimate objective of this unit is to use all the laws,
ideas, and theory's of physics covered 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 visualisation sketch, and a verbal
description. They will use this information to help them in designing their own
dragster 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 a top, front, and right side
view of a 3-D object. Again this is necessary in helping to visualize what
their dragster will look like once it is cut out of the block of wood.
Application and Review of Newton's Three Laws of
Motion
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 affects
the distance the rocket travels and also as a review how mass affects 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 develope a rocket with a film
canaster. They will develope a hypothesis, write a procedure, and record
results with a conclusion.( A nice review of the Scientific Method.)
