Jumping stick

Make a simple toy that jumps, using the elastic potential energy of an elastic band.
Science content
Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6)
Physics: Energy forms, Conservation of Energy (1, 3, 4, 5)
Lessons activity is in
  • half a sturdy bamboo BarBQ skewer
  • an elastic band, of a length that can stretch quite tightly to the bottom of the skewer
  • piece of straw, about 2cm long, that can slide over the skewer
  • two pieces of duct tape, no wider than the straw is long

Fold the elastic band flat.
Tape one end of the flattened elastic band to the end of the skewer, making the tape really tight around the skewer, so that the elastic band is held on firmly.
Slide the straw onto the other end of the skewer.
Lay the free end of the flattened elastic band over the straw and tape tightly to secure the elastic band to the straw, but without taping the straw to the skewer.

Hold the jumper upright on the desk and pull the straw down to the desk so that the elastic band is stretched.
Let go of the device in one go, by separating your fingers wide quickly.
It will jump in the air by about half a metre.

Students need to be instructed on using it safely - do not jump it towards anyone.

Ask students to think about the chain of energy transfer that happens as the toy is used.
Chemical energy - from our hands as they pull down on the toy
Motion energy - as the toy is pulled down
Elastic energy - as the elastic band is stretched
Sound energy as the device is released and the straw hits the top of the stick
Motion energy - as the elastic band pushes the toy upwards
Gravitational energy - as the toy is up in the air
Motion energy - as the toy falls back down

This activity is from the Children's Museum of Houston:

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Gr 6
Gr 7
Teaching site
MacCorkindale Elementary
Selkirk Elementary
Tyee Elementary