高空既空氣同地面係溫度同粒子排列方面有咩唔同?

Pressure arises because of the bombardment of molecules (in the air) onto surrounding objects/surfaces. The change of momenta of these molecules give rise to a force, which is the origin of pressure (pressure is the force per unit area).

Thus, the more the number of molecules, the more molecular bombardments will occur, leading to larger force (or pressure).

Q: 咩係稀薄d?個d氣壓會有咩唔同?

A: 稀薄 indicates that the number of air molecules per unit volume is less. As a result, the molecular bombardment would be less severe than that with more molecules. This casues lower bombarding force, thus less pressure.

[Note: the number of air molecules per unit volume actually is proportional to the density of air, thus places with less air molecules have lower air density]
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Q: 敢點解係個海底壓力又會大過水面,大過係空氣?

Water molecules at the bottom of the sea have to support the whole weight of water column above it plus the weight of air above the sea.

The water at the bottom is therefore compressed by these weights, resulting in an increase of water molecules per unit volume. Following the same principle as given above, the molecular bombardment would increase thus leading to a higher pressure.

Clearly, water at the sea surface only needs to support the column of air above it. Thus it is not so compressed as water at the bottom of the sea. The number of water molecules per unit volume is less (i.e. lower density) and resulted in less pressure than that at the bottom.

(1)高空的空氣稀薄d係指高空空氣的密度比較細.....而造成空氣稀薄(即單位體積的空氣較少)

(2)高空稀薄的空氣因密度細，其壓力比較細，因此其氣壓較低

(3)海底壓力係源於水的壓力
而水的密度遠遠高於空氣的密度
所以海底壓力又會大過水面，大於係空氣