1. How winds are caused?
2. Give some examples showing how air verts pressure.
3. How can you measure the direction and speed of wind?
4. What makes the balloon inflated when the boiling tube is placed in hot water?
5. Why is the same balloon deflated when the tube is kept in cold water?
Answers
1. The wind is caused by differences in atmospheric pressure which is mainly caused by temperature difference. When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area, resulting in winds of various speeds.
2. Some daily life experiences that show that air exerts pressure
You find it easier to row the boat when the wind is blowing behind you.
The wind coming from the back help in flying kite.
When we suck from the straw, the liquid rises in it.
The medicine enters the syringe when a piston is pushed out.
3. Wind speed is measured with an anemometer. Most anemometers have four horizontal shafts arranged like the spokes of a wheel. The end of each shaft is cup-shaped. The wind pushes the concave side of the cup more than the convex side, so the anemometer spins in the wind.
4. The increased volume of air fills the balloon due to which the balloon gets inflated.
5. The air then moves out of the balloon and back into the bottle, causing the balloon to deflated.