Your next challenge in 8th grade science is to build a car… You and your group (if you choose to work with a group) will build one kind of car – either one powered by a balloon or one powered by a mousetrap. Regardless of the kind of car you choose to build, there are certain “rules” you must follow.

Screen shot 2012-08-10 at 10.00.56 AM.pngAll Cars Must…
• Have two axles (axles are what hold wheels in place);
• Use wheels that were not originally designed to be a wheel;
• Remain on the ground during its entire trip.

Balloon-Powered Cars Must…
• Be powered by 1-2 balloons only;
• Travel a distance of 3 meters.
...Here is a link to a Balloon Car Video (and another one; and here's a third video)


Mousetrap-Powered Cars Must…
• Be powered by a “standard” mousetrap only;
• Travel a distance of 10 meters.
...Here is a link to a Mousetrap Car Video

Tentatively cars are due, ready to race, on October 7 (note: date change).

Note… if you have trouble getting your car to move the required distance, you will not fail this portion of the project. Even if it doesn’t move at all, you will still earn a 24/30 (80% B-). When combined with all of the other aspects of the project, there is plenty of opportunity to increase your overall grade on this project.

Here is how you will be graded on the construction of your car. It is worth 30 points total:
Screen shot 2012-08-17 at 6.39.46 PM.png
We will be using your cars to demonstrate several of the physical science concepts we are learning about... motion, speed, forces! More to come with that...


We will be chronicling the knowledge you are gaining throughout our unit on motion and forces through journals. These journals will be written as we discussing each major concept in science. All due dates for the journals are tentative (will be notified of changes as necessary). Eventually these journals will be compiled into a portfolio, either electronic or hard-copy format, to be submitted at the end of the unit for a final assessment of the physical science material.

Journal Topic
Due Date (for Draft)
Relate the motion of a balloon/mousetrap car to the following energy concepts:
1. Potential energy (when is it at its maximum? ...minimum?)
2. Kinetic energy (when is it at its maximum? ...minimum?)
3. Dissipated energy (when is it at its maximum?)
4. Energy transfer (describe how energy changes from one form into another)
5. Law of conservation of energy (explain how your car proves the law is true)
Describe how you know when your car moves (or doesn't...yet). Include the term reference point in your response. Be careful not to use a form of the word move to describe the motion of the car (example of what not to write: "I know my car is in motion because it moved.")
(date has changed since the orange sheet was distributed)
1. Name all of the forces acting on your car as it moves. Diagram these on a picture of your car.
2. Describe the motion of your car when your car demonstrates...
a. balanced forces and b. unbalanced forces.
3. Include which of the forces is the strongest (when unbalanced) and how that affects the motion of the car (slows it down, speeds it up, etc.) at the...
a. beginning and b. end of the "race.".
(date has changed since the orange sheet was distributed)
1. Describe the process you went through to design your final car.
2. Identify the issues you experienced when building your car and how you either solved them or attempted to solve them.
3. Include advice you'd offer someone taking on this challenge
or something you wish you had thought of and would do differently if you had to build another car.
(date has changed since orange sheet was distributed)
1. Calculate the speed of your car. Show how you got the average speed.
2. Include your Excel graph (we'll do these in class) and analyze the graph (your car's motion compared to the others on the graph). 3. Connect the change in speed of your car (speeds up at the beginning, slows down at the end) to either
- the forces acting on your can
- the energy your car demonstrates.
Car Project 2012-13