Can you build a LEGO car that travels the farthest?
This simple LEGO car challenge combines building, testing, and problem-solving into one hands-on STEM activity. Kids design a LEGO car, test it on a ramp, and then improve their design based on what they discover.
Along the way, they’ll explore important force and motion concepts while thinking like engineers.
Whether you’re teaching a force and motion unit, looking for a fun LEGO STEM activity, or need an easy engineering challenge for kids, this investigation is a great place to start.
👉 Explore more LEGO STEM activities here
Science Concepts
- Science Topic: Force and Motion
- Grade Level: Kindergarten–5th Grade
- Concepts Explored: Force, Motion, Gravity, Friction, Distance, Engineering Design, Problem Solving
- Difficulty: Easy
- Time Needed: 20–30 Minutes (more if desired)
What Makes a Good LEGO Car?
Engineers design vehicles to move efficiently.
In this challenge, kids will investigate how different design choices affect motion.
Questions to explore:
- Do bigger wheels help a car travel farther?
- Do more wheels help a car travel faster?
- Does a heavier car move differently?
- Does car length affect distance?
- Which design works best?
🔎 The goal isn’t to build the perfect car right away. The goal is to test ideas, make improvements, and learn from the results.
LEGO Car Ramp Challenge
Supplies
- LEGO bricks
- LEGO wheels
- Cardboard
- Books or blocks
- Measuring tape or ruler (optional)
Set Up
- Create a simple ramp using cardboard and a stack of books.
- Build a LEGO car with wheels.
- Choose a starting line at the top of the ramp and use the same starting position for every test.
The Challenge
- Release your LEGO car from the top of the ramp.
- Observe how far it travels.
- Now make one change to your design and test again.
- Can you make your car travel farther?
- Can you improve your results?
Think Like an Engineer
Before testing, ask:
- What do you predict will happen?
- Which design will travel the farthest?
- Why do you think that?
After testing, ask:
- What worked well?
- What would you change next?
- Did the results match your prediction?
🔎 Engineers rarely get the perfect design on the first try. They test, improve, and test again.
The Science Behind It
Force and Motion
A force is a push or a pull that changes how an object moves. When the LEGO car rolls down the ramp, forces cause it to move.
👉 Explore more: Force and Motion for Kids
Gravity
Gravity pulls the car downward along the ramp. This force helps the car gain speed as it travels downhill.
👉 Learn more: Gravity for Kids
Friction
Friction occurs when two surfaces rub against each other. The wheels rubbing against the floor create friction, which slows the car down.
Different surfaces create different amounts of friction.
👉 Test more: Friction Experiment for Kids
Engineering Design
Engineers solve problems through testing and improvement. This is called the engineering design process.
This challenge encourages kids to:
- Ask questions
- Make predictions
- Test ideas
- Collect observations
- Improve designs
👉 Read more: Engineering Design Process for Kids
👉 Explore more: Engineering Activities for Kids
Challenge Extensions
Try changing one variable at a time.
- Wheel Size: Do larger wheels help the car travel farther?
- Car Weight: Does a lighter or heavier car perform better?
- Car Length: Does a longer car roll differently than a shorter one?
- Wheel Placement: What happens when you move the wheels closer together or farther apart
- Surface Type: Test your car on a wood floor, tile, cardboard, cloth, or carpet
🔎 Which surface creates the most friction?
👉 Add one of these to the challenge!
Free LEGO Car Ramp Challenge Printable
Make this activity even easier with our printable LEGO Car Force and Motion Challenge.
The printable includes:
- Design page
- Prediction sheet
- Testing pages
- Engineering reflection questions
👉 Download the free LEGO Car Ramp Challenge Printable below.
More Force and Motion Activities
Looking for more ways to explore how things move?
Try these favorite activities:
- Wind-Powered Car (Make it out of LEGO!)
- LEGO Zip Line
- Balloon Rocket
- Marble Coaster
- Move It! Investigation Labs
- Push-and-Pull Ramp Experiment (Use a LEGO Car!)
FAQ
What does this LEGO car challenge teach?
Kids learn about force and motion, gravity, friction, engineering design, and problem-solving through hands-on testing and observation.
What age is this activity best for?
This challenge works well for kindergarten through 5th grade. Younger children can focus on building and testing, while older students can measure and compare results.
Do I need a LEGO car kit?
No. Any LEGO bricks and wheels can be used to complete the challenge.
Why use a ramp?
Using a ramp helps keep testing consistent so kids can focus on how design changes affect motion.
Can this be used as a science fair project?
Yes. Kids can investigate how wheel size, weight, length, or other design features affect how far the car travels.
Move It! Engineering Investigations Lab
Help kids explore force, motion, friction, airflow, and energy through hands-on engineering challenges that encourage them to build, test, measure, and improve designs.
✔ Engineering investigations that go beyond worksheets
✔ 5-day STEM plan included
✔ Engineering notebook and planning pages
✔ Build, test, redesign, and improve challenges
✔ Grades 2–5
👉 Get the Complete Lab
