Effects of moving air in Air, Winds And Cyclones – Class 7 Science Experiment
Chapter Name: Air, Winds And Cyclones
Activity Name: Effects of moving air in Air, Winds And Cyclones
Activity Description:

This experiment investigates the effects of moving air on a postcard placed on a glass. It explores how air movement can lift the postcard and its behavior when air is displaced above and below it.
Required Items:
- Glass
- Postcard
- Water
Step by Step Procedure:
- a. Place the glass on a table.
- b. Put the postcard on top of the glass.
- c. Wave your hand or notebook just above the postcard to displace the air above it.
- d. Observe what happens to the postcard.
Experiment Observations:
- When the air above the postcard is displaced, the postcard lifts up due to the pressure difference created by the moving air. Now, wet the edges of the glass with water and stick the postcard to it. Hold the glass inverted with your left hand, as shown in figure (b). c. Move your right hand or notebook to create air movement from under the postcard. d. Observe what happens to the postcard in this case.
Precautions:
- Handle the glass and postcard with care to avoid any breakage or damage.
- Ensure there is no strong wind or draft in the room that could interfere with the experiment results.
- Be cautious while using any sharp objects to avoid injuries.
Lesson Learnt from Experiment:
This experiment demonstrates how moving air can create pressure differences, leading to the lifting of objects. The air above the postcard is displaced, resulting in lower air pressure above it compared to below, causing the postcard to lift. Additionally, wetting the edges of the glass and creating air movement from below further reinforces the concept of pressure variations and their effects on objects.