Yummy Science – Spud Guns. Experiments you can try in the kitchen – Custard Bouncing Balls, Magical Water, Growing Crystals, Designer Onions, Honeycomb Toffee, Sticky Milk, Toast Busters, Toasty Science, Self Slicing Banana, Secret Messages

Science Links

More fun nutrition activities at
the Rowett Research Institute, eduweb
Check out National Science & Engineering Week at:
The BA (British Association for the Advancement of Science)

Further food science ideas for the primary aged audience are presented in the ‘Food for Thought resource, downloadable at The BA

For secondary pupils, there are lots of great kitchen chemistry ideas available in the Salters Chemistry Club handbooks or in various publications produced by the Royal Society of Chemistry

Exploring the science:

When each end of the metal tube is plugged with potato, the air inside the tube is trapped Pushing the piece of potato at one end with the wood dowel/pencil causes the air inside the tube to compress (squash up) until sufficient compression force is built up to cause the potato piece at the opposite end to fly out…. Become a rocket scientist! See how far you can get the piece of potato to fly by altering the angle of projection - try aiming horizontally and then angled upwards by increments.

Taking it further:

Which produces a better missile - an ‘old’ potato? or a ‘new’ potato?
What happens if you vary the thickness of the potato slice? or pre-soak the potato in fresh water? or if you change the length of the tube? or the width of the tube?
Set up a target and see who can get closest to the ‘bullseye’ from a set distance away.

Safety:

The ends of the metal tube can be quite sharp - the roughest bits can be smoothed with sandpaper. Do point tubes away from faces - of course there is far less mess if the potato ‘popping’ is done out of doors.

This really is rocket science! The versatile potato can be used to make a very simple rocket. See if you can use it to investigate how the angle of launch of a rocket might affect how far it goes!

You’ll need:

Some short lengths of copper tubing e.g 15mm diameter - 20cm and 30 cm lengths; 28mm diameter - 20 cm and 30cm lengths (tubing available in the plumbing section of DIY stores).
Wood dowel or pencil (it needs to fit inside the copper tubing and be approximately the same length as the tube)
Uncooked potatoes - mix of ‘old’ and ‘new’
A kitchen knife to slice the potatoes
A ruler (to measure thickness of potato slices)
Tape and/or markers (to measure how far your rocket goes!)

What to do:

Cut a slice from one of the potatoes, approximately 1 cm thick.
Take a length of copper tubing and plug both ends of the tube with potato by simply pushing the copper tubing into the potato slice - the metal cuts into the potato quite easily.
Point the tube away from you and holding firmly, quickly push the wooden dowelling into the end of the tube nearest you.

What happens:

The potato plugging the end of the tube furthest away from you should fly out making a satisfactory ‘pop’ as it goes!