Physical Phenomena

Two Balls Bounce Experiment!

Sports. One of Australia’s true loves! As we know, sports have different balls of different sizes – many that bounce. In this home science experiment, we learn about the laws of physics in a hands-on way using simply a couple of different sports balls laying around your house. Today’s video is all about energy. Energy is neither created nor destroyed (Newton’s law of conservation of energy). The video is all about transferring energy. We look at what happens when you bounce two different balls of different shapes and sizes..and why! You will be surprised by what happens.
What you need:
  • 2 bouncing sports balls, of different shapes and sizes

Key concepts
  • Physics
  • Energy
  • Collisions
First, hold the larger ball in front of you at shoulder height and let it fall without giving it a push. How high does it bounce back—almost up to your shoulder, your hip, your knee?

Repeat this a couple more times. Does the ball bounce back to approximately the same height each time?
Repeat the test with the smaller ball. Do you think it will bounce higher or lower than the larger ball? How high does this ball bounce back?

Repeat a couple more times. Are your results consistent?

Do you think the ball can bounce back higher than the height at which you released it?

Hold the larger ball in front of you at shoulder height like you did initially. Place the smaller ball on top of the larger ball so they just touch, and hold it there. You might need a helper to hold the balls in place. In a moment, you will release the two balls at the same time. What do you think will happen? Will the larger fall faster or will both stay together as they fall? How will they bounce back? Will a ball bounce higher, the same or lower than before?

Try it out and observe. You might need to try a couple of times to get the timing right. Was your prediction correct? Can you explain what you observe?

Repeat the previous step a couple more times. Are the results consistent?

Compare the balls’ masses. Was the top ball (the smaller one) heavier or lighter than the bottom ball?

Hold the smaller ball in front of you at shoulder height like you did initially and place the larger ball on top. What do you think will happen when you release both balls at the same time?

Perform the test a few times. Was your prediction correct? Can you explain your observations? Note that although before the larger bottom ball was probably heavier than the smaller top one, this time the top ball is heavier.

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