Pressure, Winds, Storms and Cyclones
NoteWhat This Chapter Covers
Why does a heavy bag hurt less with broad straps? Why is an overhead water tank placed high up? Why can a storm rip the roof off a house? The answer to all three is one powerful idea — pressure, the force spread over an area. This chapter builds pressure from the ground up, shows that liquids and air press in every direction, and then follows pressure differences out into the sky, where they stir the winds, brew thunderstorms with lightning, and spin up the most dramatic weather of all: the cyclone.
Learning Outcomes
By the end of this chapter, you will be able to:
- define pressure as force per unit area, calculate it, and state its unit, the pascal (Pa);
- explain why a larger area lowers pressure (broad straps) and a smaller area raises it (a sharp knife);
- show that liquids and air (atmospheric pressure) exert pressure in all directions;
- explain how a difference in air pressure causes wind, including land and sea breezes;
- describe how thunderstorms and lightning form, and the safety rules during them;
- explain how a cyclone forms over warm oceans, name its eye, and describe how the IMD keeps us safe.