Does Height Affect Speed?

Roller Coaster Engineering kit with modular frame and flexible red track for building and testing physics-based roller coaster models

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The Big Question

Does changing the starting height of a roller coaster affect how fast the train travels?

Make Your Prediction

What do you think will happen when the train starts from a higher point? Will it travel faster, slower, or at the same speed? Explain your prediction.

What You'll Need

• Roller Coaster Engineering kit by Thames & Kosmos
• Stopwatch or phone timer
• Measuring tape or ruler
• Paper and pencil to record results
• An adult helper, if needed

Let's Experiment!

  1. Build a roller coaster with an adjustable starting hill using your kit's instruction manual.
  2. Choose a starting height and measure it with a ruler.
  3. Release or launch the train using the same method each time.
  4. Time how long the train takes to travel between two marked points on the track.
  5. Repeat the test three times and record your results.
  6. Raise the starting hill, keeping the rest of the track unchanged.
  7. Repeat the experiment at three different starting heights.
  8. Calculate the average travel time for each height. Which height produced the shortest time?

What Are We Measuring?

What you change: The starting height of the roller coaster.

What you measure: How many seconds the train takes to travel the same section of track.

What stays the same: The train, track distance, track shape, timing points, and launch method.

Science fair tip: Repeat each test three times and calculate the average to make your results more reliable.

The Science Behind It

A roller coaster at the top of a hill has gravitational potential energy. As the train travels downhill, some of that energy changes into kinetic energy — the energy of motion.

Starting higher can give the train more energy and allow it to reach greater speeds. Friction between the train and track also affects its motion.

Think about it: Did your results match your prediction? Why might two tests at the same height produce slightly different results?

Ready to Be a Scientist?

Every great scientist records their discoveries! Download your free experiment worksheet to make a prediction, track your results, and explain what you learned.

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Ready to Try It Yourself?

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