Materials required: - paper and scissors
Cut a long strip of paper with a breadth of 2 cm. Hold one edge between your fingers. Put your lip above one end of the strip. Blow hard. See how the strip lifts itself up horizontally like a wave.
How does it lift itself up?
When you blow hard the air on the top the strip is pushed away and the air at the bottom lifts the strip. In an aero plane the fan sends a violent current of air which clears the air under the wings. Air pressure below lifts the plane.