Pressure, Winds, Storms, and Cyclones

Overview

Pressure is the force acting on a unit area. Air around us exerts pressure called atmospheric pressure. Differences in air pressure cause winds, which can become storms and cyclones.

Key concepts

• Pressure is force per unit area; smaller area gives more pressure.
• Air exerts atmospheric pressure in all directions.
• Warm air rises and creates low pressure; cool air moves in as wind.
• High-speed winds and water vapour can form storms and cyclones.
• Cyclones cause heavy rain, floods, and damage.

Important terms / formulae

• Pressure = Force / Area.
• Atmospheric pressure: pressure exerted by air.
• Cyclone: a system of high-speed winds around a low-pressure centre.
• Wind: moving air caused by pressure differences.

Solved example or key process

1. A force of 100 N acts on an area of 2 m².
2. Pressure = Force / Area.
3. Pressure = 100 / 2.
4. Pressure = 50 N/m² (pascal).

Important questions

1. Define pressure and give its formula.
2. Why does air pressure cause winds?
3. How are cyclones formed?
4. List safety measures during a cyclone.

Quick revision

Pressure is force per unit area. Air presses in all directions. Unequal heating of air causes pressure differences and winds. Strong winds with moisture form storms and cyclones, so early warnings and safety steps are important.