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Physics for Secondary Schools
Chapter Seven
Pressure
Introduction
Pressure has many infl uences on daily life. Knife edges are made sharp to allow
easy cutting while football shoes consist of spikes that help the player to have
a better grip on the ground. School bags are made with wide shoulder pads to
reduce pain on the shoulder and a person carrying a clay pot uses head rings to
reduce pain on the head. All these facts can be explained using the concept of
pressure. In this chapter, you will learn about the concept of pressure in solid,
liquid, and gas and its applications in daily life situations. The competencies
developed will enable you to effectively utilise different tools that operate under
the principle of pressure.
Think
why wearing shoes with high heels is not advised on soft ground
Concept of pressure
Consider an iron nail being driven into a piece of a block of wood through its sharp end
as in Figure 7.1 (a) and the fl at end as in Figure 7.1 (b). The iron nail with the sharp point
will penetrate easily into the block of wood. On the contrary, when it is driven into the
same block through its fl at end with the same magnitude of force, it will not penetrate
easily.
Hammer
Hammer
Nail
Nail
Wood
Wood
Sharp end of a nail driven into a wooden block Flat end of a nail driven into a wooden block
(a) (b)
Figure 7.1: Driving an iron nail into a block of wood
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Student’s Book Form One
Physics Form 1 Final.indd 136 16/10/2024 20:57
