Beat the Carnival Game

Beat the Carnival Game

Have you ever played the carnival game One Ball? All you do is try to knock over stacked bottles with a ball. It looks easy, but it's surprisingly tricky to knock down all three bottles. What makes it so difficult? You guest it: balance. 

Let's investigate! 

5 - 8
Est. Time:
1-2 hours

How we did it:

Materials List

  1. tennis ball
  2. measuring tape
  3. plastic bottle (3) - make sure they're identical!
  4. water
  5. food coloring (3) - different colors
  6. notebook
  7. pencil
  1. 1. Start by setting up your experiment on a flat surface. 

    - Fill each bottle with the same amount of water. Add a few drops of food coloring. 
    - Set them up in a pyramid. 
    - Measure a few feet away and mark your throw line. 

  2. 2. Throw the ball at the pyramid from the throw line. Repeat 6 times for each experiment, and record your results. Try to hit different spots and see how many bottles you can knock down each time. 

    - Experiment 1: all bottles filled
    - Experiment 2: bottom bottles filled
    - Experiment 3: top bottle filled

  3. 3. Grab a notebook and record your results. Each time you hit the pyramid, make a note of where you hit it and record the number of bottles you knocked over. Try to hit the same spot in all 3 experiments to see what difference the setup makes. 

  4. Answer These Questions!

    - Which pyramid was the easiest to knock down? Which was the hardest? 

    - Did throwing the ball in the same place work for all three pyramids? Did you need to hit different places?
    - How do you think the One Ball game at a carnival is usually set up? 

  5. What's going on?

    In these experiments, you change which part of the pyramid is heavy and which part is light. In Experiments 1 and 2, the bottom of the pyramid is heavier than the top. In Experiment 3, the top is heavier than the bottom. 

    It's difficult to knock over all 3 bottles in Experiment 1, and even harder in Experiment 2! If you throw the ball right, in the middle, you'll likely only knock over the top bottle, leaving the bottom two standing. 

    In Experiment 2, on the other hand, the pyramid is pretty easy to knock over. If you hit this pyramid in the middle, there's a good chance all 3 bottles will fall. 

    By moving the weight, you change how the pyramid balances. An object with a lot of its weight down low is better balanced than an object with a lot of weight up high. So if you want to make your game of One Ball really easy, just make the bottom of your pyramid light and make the top as heavy as you can!