Object Shape and Air Resistance

Materials required: stiff paper, a scale, paste, thread, scissors and an electric fan.
Make three card board tubes as shown below. 1. is a cylindrical tube. 2. is a square tube. 3. is a tube having the shape of dropping water. Tie up the three tubes separately on a common beam, or support. Let them hang where there is breeze; or use an electric fan. Which shape gets pushed very much and which is less? The flat surface gets pushed very much, the cylindrical tube gets pushed a little less, and the third one is the lea: t. You will notice that air resistance is very much reduced if the shapes has curved surfaces. That is why modern cars and locomotives, especially race cars and aero planes have got conical cal and smooth curved surfaces. They have less air resistance and therefore they can move with a great speed.
























