Hot Wheels Crash Test Dummy Part II – Test a Hypothesis


**NOTE** This activity is in 2 posts.  Check out Hot Wheels Crash Test Dummy Part I – Inertia to view the initial set-up of the experiment and explanation of INERTIA.

Making a hypothesis and recording data are steps in the Scientific Method (I know at least half of my readers are probably groaning or cringing when they read this phrase!).  But listen, the Scientific Method is what most standardized testing for our students is based around to get them ready for the Science portion of the ACT.  The ACT/SAT may seem far off for your 5-yr-old… but imagine how great it would be if your kid starts school already feeling comfortable with science terms and using a scientific approach to problem solving!


Hypothesis – an educated guess about what will happen in your experiment.

Data – the information you gather during your experiment. (In this case it will be the distance we measure.)

Data Table the chart used to keep track of (and make sense of) the data you collect


  • Hot Wheels car (They usually sell for $1 at any grocery store.)
  • Play-Doh (It helps if it is relatively fresh, so it will be more sticky.)
  • Stack of books (or a box)
  • Tape (Masking tape works best)
  • Pencil (a pen, marker, or good ole stick will also work)
  • Hot Wheels ramp or track (if you don’t have this, just make one out of cardboard!)
  • Ruler or measuring tape
  • Construction paper (or any scrap paper will do)


  1. Follow the set-up guidelines in Hot Wheels Crash Test Dummy Part I – Inertia to build the ramp and the crash test dummy Mo.
  2. Make a HYPOTHESIS!  What does your child think will happen to Mo when he and the car roll down the ramp and crash into the pencil? (If they are old enough to write, have them write their hypothesis at the top of the paper.) Why do they think this will happen? (This is always the hardest part, even for my high school students back in the day.  You may need to prompt your child to come up with a reason for their hypothesis – “Is it because he is not strapped down onto the car?” etc.)
  3. Draw a DATA table! On the construction paper draw a very simple chart with 2 columns, one to keep track of each trial run down the ramp and one to write down the distance that Mo flew off the hood of the car.  (If your child is old enough to draw, they can make this with just a little guidance. I used the edge of a coloring book to draw straight lines.)

    Simple data table
  4. It is time to run the experiment!  Hold the car with Mo on the hood at the top of the ramp and let it go.  You should expect the car to hit the pencil and stop, but Mo continues to move forward off the hood of car and lands some distance in front of the pencil – Mo has INERTIA!  (As with all experiments conducted outside of a highly precise lab environment, it won’t work perfectly every time.  But that’s ok – that’s why we call it “experimentation!”)
  5. Use the ruler or measuring tape to measure the distance between the pencil and where Mo landed.  Write down this number in your data table. Send Mo down the ramp at least 2 more times and write down his distance.

    Mark and measure the distance Mo travelled past the pencil.
  6. Compare what actually happened to your child’s HYPOTHESIS. Let them know that it’s okay if their hypothesis wasn’t right.  That’s the great thing about science: they can make a new one before they run the experiment again! Try the experiment as many times as they want, but encourage the kids to keep measuring as long as their attention span holds out.
  7. Kids may want to change the experiment by raising or lowering the ramp, making Mo bigger or smaller, putting the pencil further away, etc.  They can make a new hypothesis and draw a new data table for each change they want to test! (If your child is older, you can take DATA a step further and calculate AVERAGE DISTANCE by adding up all distance numbers and dividing by the number of trials you ran!)

    Draw a new data table for each new hypothesis


Science is actually really simple when you boil it down. 1) Identify a question: What will happen to Mo when he and his car hit that pencil?  2) Make a hypothesis: Hm, we think he’ll fall off the side because he’s not attached to the car very well.  3) Run your tests and write down what happened in your data table. 4) Make a conclusion: Was your hypothesis right?  If not, what DID happen?

Happy experimenting!  And as always, if you liked it, share it! 🙂


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