Science Projects Index

See-Saws and Levers

You must have played on see-saws in the park. Did you know that it is a first class lever? If two children of equal weights sit on either end the weights will be balanced. If one child is bigger, then he can easily lift the other boy. But if the big child moves nearer to the pivot, then the small child will be able to balance the see-saw. At the same time, if the big child moves more nearer to the pivot, then the small child can even lift the big child, on the see-saw. This is the principle of levers.

Air Turbines

Take a round piece of cardboard and make a hole in its centre. Then cut it as shown in the figure. After cutting it, bend the wings to an angle as in a fan. Now insert a thick wire through the central hole and place it on a stand as shown. Blow air on to the blades and you will see them rotating like a turbine.