Great clip from last nights “Bang Goes the Theory” – a water powered jetpack

and remember, don’t try this at home.

From the BBC’s Bang Goes the Theory site.

Full instructions can be found here.

Rockets work by ejecting something out of the back and a so-called ‘reaction force’ then pushes the body of the rocket forward.

Here, water and air are shoved out the back. The water is heavier so that’s what gives the bottle the main kick forwards.

The energy to force the water out is stored as air pressure inside the bottle. You supply the energy as you pump air into the bottle.

The air pressure inside builds up and pushes on the water. But friction holds the cork in place and that pushes back on the water, so for a while nothing moves.

Once the friction force can no longer contain the pressure, the cork is shoved out and the pressure then acts on the water to eject it from the bottle.

Compared to the bottle, the water is heavy. So pushing water out at a moderate speed backwards gives the bottle a lot of forward speed.

This week, BBC One launches Bang Goes The Theory, a brand new series with a hands-on approach to science.

Presenters Jem Stansfield, Liz Bonnin, Dallas Campbell and Dr Yan Wong will pool their knowledge and curiosity to challenge the scientific principles that shape our world. It will include a series of experiments, one of which will see one of the show’s presenters, Dr Yan, being dramatically transported across a 2.5m void via magnetism: a method selected by the general public.

The series, co-produced with The Open University (OU), will be supported by free events and an interactive website. You too can do real science online and at home. It aims to bring all ages together with accessible science that encourages everyone to get their hands dirty. The Bang Goes The Theory blog, which is updated daily, will slowly establish the show — with a series of videos and exclusive pictures that follow the progress of the conception, testing, building and trialling of the contraption. A number of explanatory videos are already online.

Sounds like it could be a fun programme – a slight shame it’s going out right at the start of the school holidays so teachers can’t follow up on it immediately in the classroom.

Keep an eye on the show, and hopefully there will be clips you will be able to use after the Summer break which could be used to spark off exciting science investigations.

The BBC have launched an area of their gardening website aimed at children. There’s some nice ideas for gardening projects both indoors and outdoors. Take a look and see if any could be used with your class.

http://www.bbc.co.uk/gardening/gardening_with_children/homegrownprojects_index.shtml