Newton's laws experiments for kids: 3 easy toy car activities

Why toy cars are the perfect way to teach Newton's laws

Your child has probably zoomed a toy car across the floor a hundred times. That push, that crash into the baseboard, that dramatic flip off the ramp. It's all physics in motion. Literally.

Toy cars are one of the best tools for teaching Newton's laws because they demonstrate all three: starting, stopping, crashing, and ramping. You don't need a lab or special equipment. The playroom is already a classroom; you just need the right vocabulary for what's happening.

These three Newton's laws experiments for kids take something your child already does and turn it into a hands-on science lesson. Each one maps to a single law of motion, uses items you already have, and takes about five minutes to set up. They also pair naturally with our Isaac Newton picture book, which gives kids the "who figured this out?" backstory behind the experiments they're about to run.

Find the Isaac Newton picture book here →

Meet Isaac Newton (the kid-friendly version)

Isaac Newton was born in 1643 in England. He grew up on a farm, was a curious and somewhat solitary kid, and eventually became one of the most important scientists in history. The famous apple story, where a falling apple supposedly sparked his thinking about gravity, is a popular tale, though historians debate whether it happened exactly that way [VERIFY: apple story — widely told but historically disputed; confirm sourcing before publishing]. What's not in dispute is that Newton published his three laws of motion in 1687 in a book called Principia Mathematica, and those same three rules still describe how everything moves, from toy cars to spacecraft.

If you want the fuller story, our Isaac Newton biography post goes deeper. You can also read about the Newton apple story for a fun look at that famous legend. But for the experiments below, here's what you need.

Newton's 3 laws in one sentence each

Here's your cheat sheet before you start. Law 1 is inertia: things keep doing what they're doing until something makes them change. Law 2 is force and motion: a bigger push makes things go faster, and heavier things need a bigger push. Law 3 is action and reaction: every push comes with a push back.

That's it. Those three sentences are your script for the next three experiments.

Experiment 1: the sudden stop (Newton's first law: inertia)

This is the classic "passenger keeps going" demo, and it's the simplest of the three. You'll show your child how an object in motion stays in motion, even when the thing carrying it comes to a halt.

What you'll need

• 1 toy car
• A small lightweight figure (LEGO minifigure, Playmobil person, or even a small eraser)
• A flat floor or table
• A book or wall as the "crash barrier"

How to do it (step by step)

1. Place the small figure loosely on top of the toy car. Not clipped in, not taped. Just resting there like an unbuckled passenger.
2. Roll the car at a moderate speed toward the book or wall.
3. Let the car crash into the barrier and stop suddenly.
4. Watch what happens to the rider.

Ask your child before you roll: "What do you think will happen to the little person when the car stops?" Let them guess. Then run it.

What's happening (and how to explain it to your kid)

The car stopped because the wall pushed back on it. But the little rider didn't have anything pushing on them, so they kept moving forward. That's Newton's first law in action. Objects in motion stay in motion until a force stops them.

This is exactly why we wear seatbelts. Without a seatbelt, a person in a car that stops suddenly would keep going forward, just like the toy figure did. The seatbelt is the force that stops you.

One thing to point out: the car didn't "throw" the rider forward. The rider kept going on their own because nothing stopped them. That's inertia, plain and simple [VERIFY: confirm this misconception is commonly cited in science education literature so the claim is defensible].

Experiment 2: the ramp race (Newton's second law: force & mass)

This one is a race, and kids love races. You'll test how force (the steepness of the ramp) and mass (added weight) change how far and how fast a toy car goes. It's one of the most visual toy car physics experiments you can do at home.

What you'll need

• 1–2 toy cars (same type if possible)
• A ramp (a cookie sheet, a board, or a stack of books with stiff cardboard on top)
• A few coins or small magnets as weights
• Tape
• A floor with room to roll

How to do it (step by step)

1. Build your ramp by propping one end of the cookie sheet or cardboard on a stack of books. Start with a gentle slope.
2. Place the toy car at the top and let go. Don't push it, just release.
3. Mark where the car stops with a piece of tape.
4. Now add weight: tape a coin or two to the top of the car and run it again. Mark where it stops.
5. Raise the ramp by adding another book and run both the light and heavy car again.
6. Compare the distances.

Before each run, ask your child: "Which car do you think will go farther, the light one or the heavy one? What about if we make the ramp steeper?" Predictions make the results stick.

What's happening (and how to explain it to your kid)

Newton's second law says that a bigger push makes things go faster, and heavier things need a bigger push to get moving the same amount. A steeper ramp gives the car a bigger push (more force from gravity), so the car goes faster and farther. When you add weight, the car needs more force to travel the same distance. On the same ramp, the heavier car might not go as far as the lighter one [VERIFY: rolling physics with added mass depends on friction, rotational inertia, and ramp angle — confirm the simplified claim holds for typical toy car setups].

In kid terms: more push, more zoom. Heavier load, more push needed.

If your child starts asking "but why does the ramp make it go faster?" that's the perfect moment to pull out the Isaac Newton picture book. Newton was the person who figured out these rules over 300 years ago, and kids who love the "why" behind things tend to love meeting the curious kid who became the scientist.

Find the Isaac Newton picture book here →

Experiment 3: the balloon rocket car (Newton's third law: action–reaction)

This is the showstopper. Something about a balloon-powered car makes kids lose their minds in the best way. It's also the clearest demonstration of Newton's third law: every push comes with a push back. If you're looking for physics experiments at home that make kids gasp, this is the one.

What you'll need

• 1 toy car (any kind with smooth-rolling wheels)
• 1 balloon
• Tape
• A smooth floor (tile, wood, or linoleum works best)
• Optional: a drinking straw

An adult should handle the balloon for children under 5. Un-inflated and popped balloons are a choking hazard for young kids, so supervise closely and discard any broken pieces immediately [VERIFY: confirm balloon safety guidance matches current CPSC or pediatric safety recommendations].

How to do it (step by step)

1. Inflate the balloon and hold the nozzle closed with your fingers. Don't tie it.
2. If using a straw: tape the straw to the top of the toy car, then thread the balloon nozzle through the straw so the balloon sits above the car. If not using a straw: tape the balloon directly to the car with the nozzle pointing backward.
3. Place the car on the floor, nozzle facing away from the direction you want it to go.
4. Let go of the nozzle and watch the car zoom forward.

It may take a couple of tries to get the tape and balloon position right. That's part of the fun. Let your child tinker with it.

What's happening (and how to explain it to your kid)

The air rushes out the back of the balloon. That's the action. As the air pushes backward, the car gets pushed forward. That's the reaction. Newton's third law says every push has a push back, and this experiment makes it visible.

This is the same principle that rockets use. A real rocket burns fuel and pushes hot gas out the bottom, and the rocket gets pushed upward. The balloon car does the same thing, just with air instead of fire [VERIFY: analogy is sound — confirm no oversimplification that could mislead in an educational context].

Your child doesn't need to understand rocket science to feel the concept. They pushed air out the back, and the car moved forward. Every push has a push back. That's the whole lesson.

Turning these experiments into real learning

The experiments are the fun part. But the learning happens in the conversation around them. Here are a few ways to make the moment stick.

Ask "what do you think will happen?" before every run. Predictions get your child thinking through cause and effect before seeing the result. Even wrong predictions are valuable. They make the actual outcome more surprising and more memorable.

Let your child change one thing at a time. Raise the ramp. Add weight. Switch from carpet to tile. Each change is a mini-experiment, and it teaches them that scientists test one variable at a time. For more printable activities and STEM activities for kids, check out our resources page.

You don't need to be a scientist to do this. Curiosity is the whole lesson. If your child asks a question you can't answer, that's a win. Write it down and look it up together. For more on how Newton's laws show up in daily life, our Newton's laws in everyday life post connects these ideas to things your child already knows.

Easy ways to extend the fun

Use a ruler or measuring tape to record how far each car goes, then make a simple bar chart on paper. Your child just did data collection.

Try running the same car on carpet, tile, and wood. The car goes different distances because of friction, which opens up a natural follow-up conversation about surfaces.

Have siblings or friends predict which car will win, then test it. Kids who make a prediction get more invested in the outcome.

If your child enjoyed the ramp experiment, our gravity experiments post takes the concept further with more hands-on activities.

From experiments to story time

After a morning of crashing cars and launching balloon rockets, your child has felt Newton's laws with their own hands. They've seen inertia, tested force, and watched action and reaction happen on the living room floor. That's real science.

The natural next step is story time. When kids meet Isaac Newton as a curious kid himself, someone who asked questions about how things move and then spent his life answering them, the science they just experienced becomes a story they can carry. The experiments gave them the feeling. The book gives them the person behind it. And if you're looking for more Newton's laws experiments for kids to add to your next rainy afternoon, the three above are a solid place to start.

If you haven't read it yet, that's the perfect place to start. Kids love jumping into these experiments right after story time.

Find the Isaac Newton picture book here →