Produced by the Institute of Physics, this Physics to Go video shows a demonstration of how the idea of pressure can be shown using just a 35mm film canister, some water and an effervescent tablet. When water is added to the effervescent tablet, bubbles of carbon dioxide gas are given off. When the lid is fitted tightly to the canister this gas is contained within an enclosed space. As more gas is given off the pressure inside the canister rises until there is enough force to overcome the seal of the lid. The built-up pressure exerts enough force to shoot the canister into the air. The teachers' notes include lists of the equipment needed, tips and a full explanation of the physics involved.

Show health and safety information

Please be aware that resources have been published on the website in the form that they were originally supplied. This means that procedures reflect general practice and standards applicable at the time resources were produced and cannot be assumed to be acceptable today. Website users are fully responsible for ensuring that any activity, including practical work, which they carry out is in accordance with current regulations related to health and safety and that an appropriate risk assessment has been carried out.


You might also like

Published by


Share this resource

Lists that tag this content



Mike Grocott (not verified)

These pop rockets can be used for so many things in terms of investigations. Loads of variables, size of tablet, powder or tablet, pH of liquid, type of liquid etc. The measurement of results, time to pop, altitude achieved.  Great for developing investigative skills, however USE EFFERVESCENT ORANGE TABLETS, they are cheaper but more importantly ALKA-SELTZER tablets contain ASPIRIN and so a risk exists of students ingesting aspirin  in terms of contact with tablet residue.

Jane Banham

These are great practical investigations which children from a variety of ages can get involved in . With the demise of the film canisters in which to  carryout these investigations TTS sell a set of similar sized canisters which can be used for the same purpose.These were super to allow children to create their own question (Yr4 in my case) to investigate whilst at the same time allowing the teacher to know  what resources need to be available for the range of investigations to take place.

I'm looking forward to using this as part of a whole school rocket day to accompany the launch on 15th December.