Balloon Cars

Objective: Students will design and build a "car" that will successfully travel 2 meters (minimum) displacement required for which students will earn maximum points.

Design Parameters:

• Car may either have four wheels like a car or three wheels like a tricycle.
• Propulsion can only be provided by the maximum of two nine-inch balloons.
• Wheels may be built out of any available materials of your choosing.
• Students will mount a straw to their car to which the balloon will be attached.
• The body of the car can be built out of any available materials.
• There are no height restrictions.
• Cars cannot be longer than 30 centimeters.

Requirements:

• Cars must have a minimum displacement of two meters.
• Additional points will be awarded for cars traveling further.

Grading:

1. Design: 25 points

• Students using wheels from toy cars or other commercially available wheels will lose 5 points.
• Students using commercially available bodies for their cars (such as toy cars) will lose 5 points.
• Cars longer than 30 centimeters will lose 5 points.
• Students building a car out of readily available materials will earn maximum design points.

2. Performance: 25 points

• Cars having a minimum displacement of 1.0 meters will earn 5 points.
• Cars having a minimum displacement of 1.5 meters will earn 10 points.
• Cars having a minimum displacement of 2.0 meters will earn 15 points.
• Cars having a minimum displacement of 2.5 meters will earn 20 points.
• Cars having a minimum displacement of 3.0 meters will earn 25 points.

3. Experiment Design: 25 points

• Students must submit (individually) an experimental procedure describing what steps they must take to collect data.
• All data must be listed.

4. Questions: 25 points

Questions are worth five points each. Students must submit their answers to questions individually.

• Describe your initial design. Describe how your design evolved into the one that you used. What did you alter about your original design and why?
• Describe the motion of your car. Did it run at a constant speed or accelerate constantly?
• Why do you feel that your car ran at constant speed or accelerated constantly? (In your explanation describe the forces involved.)
• Calculate the average speed of your car. State the distance your car went and the time that elapsed.
• Apply Newton's Third Law to your car.