Museum at Home

Animal Athletes Challenge 3 | High Jump

Greatest Human Achievement

The male record for the high jump is 2.45 m (1.3 times body length) and was set by Javier Sotomayor from Cuba in 1993. The female record is 2.09 m and was set by Stevka Kostadinova from Bulgaria in 1987.

Animal Competitor 1: Flea

Amazing ability

Fleas can jump 18 cm high (100 times their body length). 

Built for jumping

  • Long back legs
  • ‘Spring’ inside leg that is compressed by the leg muscles then released to jump
  • Spines near feet on back legs grip the ground before take-off

Where do they live?

Hopefully, not on your dog or cat. Fleas live and feed on the blood of mammals and birds. The most common flea in Australia is the cat flea, which attacks not just cats, but dogs, rats, humans and other mammals.

Animal Competitor 2: Brolga

Amazing ability

Brolgas can leap 1 metre into the air as part of their courtship dance.

Built for jump 'dancing':

  • Dance includes jumping in the air with stretched out wings, and bowing and bobbing their head
  • Long wings (up to 2 m across) stretch out to give them lift
  • Long legs with springy toes

Where do they live?

Brolgas live in wetlands and are most common in north-east Queensland. They are the official bird emblem of Queensland and appear on the Queensland coat-of-arms.

At Home Challenge

You will need:

  • Animal Athletes Challenge Sheet 
  • Bouncy ball. BONUS! See below on how you can make your own simple bouncy putty at home.
  • Measuring tape or ruler
  • Paper to mark heights on
  • Sticky tape
  • A partner

What to do:

For your jump

  • Sticky tape paper together to make a strip about 1 metre long.
  • With the ruler or tape measure, make a mark every 5 or 10 cm and number them.
  • Sticky tape the strip to a wall inside, where there is a hard floor. Make sure the 100cm mark is at the top.
  • One person drops the ball (do not throw) from one of the heights. This is the release height.
  • The other person watches where the ball bounces to. This is the rebound height.
  • Try it three more times to check that the rebound height is the same.
  • Record the release height and the rebound height on your sporting profile. Are they different?
  • Record your best jump on your Challenge Sheet

To make this activity into a scientific experiment you need to identify a variable:

  • Try different release heights
  • Try different types of bouncy balls

What’s happening?

How high something bounces depends on the force at which it is dropped and its elasticity. When you drop the ball, the force is gravity. When the ball hits the ground it is compressed, or squished, and because it is elastic it springs back and pushes against the ground making it shoot up into the air.

But some of the energy from dropping the ball is changed into heat when it hits the ground so it doesn’t have the same energy when it rebounds and therefore won’t bounce as high.

You can get a ball to rebound to the same height by pushing it down. This adds energy. 

Video your results, post them online and tag #museumoftropicalqld #qldmuseum

At Home Activity

Make a bouncy ball using cornflour and water

You will need:

  • cornflour
  • food colouring
  • water
  • microwavable bowl
  • microwave
  • stirrer

What to do:

    In bowl, mix 2 tablespoons of cornflour with 30 ml water (1 tablespoon + 2 teaspoons).
  • Add 1 drop of food colouring and mix.
  • Microwave for 30 seconds.
  • Do not touch the mixture. It will be hot.
  • Let it cool down for about 2 minutes.
  • Use your palms to roll the mixture into a ball.
  • It’s ready to bounce!

What’s happening?
Heating the mixture breaks some of the bonds between molecules within the cornflour polymer. When it cools down, the molecules bind together again to create a springy mesh.

Image credits: Michael Wunderli & Dorothy Jenkins / Flickr