|
Vehicles In Motion
The Learning
By Design™ Vehicles in Motion challenge has
students build a "coaster car" -- a vehicle
without an engine -- from plans given to them at the
outset of the unit. Students are then asked to redesign
and improve upon the performance of their "coaster
car" so that it rolls down a hill and coasts as
far as possible. Teams then experiment with different
propulsion systems so that their vehicle is propelled
by a balloon-straw, rubberband, and falling-weight propulsion
systems. They then combine different ideas to create
a "hybrid car" that climbs two test hills
under its own power and then travels the greatest distance.
While working on the unit, students use Newton's Laws
of Motion to explain why their cars went straight or
not, and how their propulsion systems work.
In the first third of MOVIE 1, you will see Alpharetta,
GA, science teacher, Leslie Baker, guiding her students
who are in the middle of their work and are testing
their balloon powered model cars. Listen carefully to
the diagnostic reasoning students give for their cars'
performance. Use QuickTime's frame-by-frame way of viewing
the cars' tests. In the rest of Movie 1, you can hear
students describe the Design
Rules-of-Thumb they derived from their own experiments
to help themselves and others make Informed
Designing decisions about their car's wheel size,
bearing type, wheel tread, method of propulsion and
way of connecting rubber bands to their car's rear axle
(what in Movie 1 are called the J-Post and X-Post methods).
Notice that students have not fully grasped the reason
why cars driven by rubber bands (which produce high
torques on the axles and wheels) spin out when initially
released. (Hint: Large and small wheels have the same
torque, but the force of the wheels on the road with
small-diametered wheels is much greater than for large
wheels -- Torque = Force X Distance.)
- 1 piece of 8x30 cm foamcore or cardboard
- 2 6-inch carriage bolts, coarse 1/4" thread
- 4-6 1/4" thread regular nuts
- 2-4 1/4" thread wing nuts
- 1 roll masking or other tape
- 2-3 plastic or paper straws
View or print out copies of the Vehicles In Motion student and teacher materials by clicking below:
|
