Children investigate how levers work, using tug of war equipment. When the girls are unevenly matched with the boys, they discover that moving the rope gives them more pulling power with less effort. A giant syringe has a dropping ball, which forces air through its tube to move a tennis ball upwards. Children experiment with compressed air, discovering how much force it will take to lift heavy weights. Pumping up a balloon forces more air into the same space, demonstrating how, when air is compressed, its pressure increases. When a force created by air pressure is very strong, it is called a 'pneumatic force'. Forces drive everything, so we need to have an understanding of how they work.

This clip is from:
Primary Focus Science
First broadcast:
15 April 2008

Could be used as part of a topic on forces. Pupils could discuss examples of forces used in everyday life. The clip could be paused after each investigation and similar supervised practical activities could be set up: tug-of-war, using coins and screwdrivers to lift lids off tins and compressed air investigations could be undertaken. Pupils could devise their own investigation and include all aspects of fair testing. Further research could be done on levers and pneumatic force and how they are used in the world around us. Another extension idea would be to look at how levers were used in history, for example, during the building of the pyramids in Ancient Egypt.