Build the car shown in the picture. Test your car by setting it on the ground. Does it move easily? If not, you may be gearing up instead of down. Try turning the worm gear capsule around. 

1. Make a Race Track
   Set up a straight race track that is 10 feet long.
   Use tape or chalk to clearly mark the start and finish lines.

2. Test Your Car
   Use a stopwatch to time how long it takes your car to go from the start to the finish line.

3. Calculate Speed
   Use this formula to find your car’s speed:
   Speed = Distance ÷ Time
   (Example: If your car travels 10 feet in 2 seconds, the speed is 5 feet per second.)

4. Record Your Results
   Write your speed in your STEM Journal.

5. Repeat
   Run the test a few times and record each result.

6. Fix Swerving Cars
   If your car swerves or turns, adjust the front and back axles so it goes straight.

1. Change Your Car Design
   Use what you know about gear ratios to change your car and try to make it go faster!

2. Test the Speed
   Run your car on the same 10-foot track.
   Use a stopwatch to time how long it takes.

3. Calculate the Speed
   Use the formula:
   Speed = Distance ÷ Time
   (Distance is still 10 feet.)

4. Record Your Results
   Write down your car’s speed in your ePortfolio.
   How does it compare to the speed of your basic car?

5. Keep Experimenting!
   Try different gear capsules or change the order of the gears.
   Each time you make a change:

• Test your car

• Record what you changed

• Record the new speed

What Affects Your Car?
Think about other things that might change your car’s speed, like:

• Low battery power

• Worn-out parts

• Friction from the floor
  If your results aren’t what you expected, try to figure out why!