Page 65 - Physics Form 5 KSSM_Neat

Pressure at an Extreme Depth under the Surface of the Sea CHAPTER 2

At an extreme depth under the surface of the sea: I GALLERY Pressure
• Water pressure increases with its depth • A diver who dives to a depth of
• An increase in depth of 10 m causes an increase in water pressure 30 m in search of pearl oysters
by 1 atmosphere will experience a pressure 4
KEMENTERIAN PENDIDIKAN MALAYSIA
• Water pressure and atmospheric pressure are experienced times the normal atmospheric
pressure.
Effects on human beings at extreme depth under the surface of the sea • Submarines moving to a depth
• Body tissues absorb excess nitrogen gas of 240 m experience a very high
• Nitrogen gas dissolves into the blood pressure, which is 25 times the
• Inability to think clearly pressure at sea level.
• Formation of nitrogen bubbles in the tissues or blood vessels if
pressure is reduced too rapidly

SCAN ME
Adaptations and actions SCAN ME
to be taken Video of formation
of nitrogen bubbles
in the tissues or
blood vessels
https://bit.ly/VidNitro
Divers Submarines
• Do physical exercises • Submarine is made of steel or
to enable the body to titanium with a circular cross
adapt to a high pressure section to withstand the high Booth
environment before diving pressure of surroundings
• Wear a diving suit to • Pressure in the cabin of the Professional divers can serve in the
navy, work as commercial divers or
slow down heat loss submarine is controlled to almost serve as recreational trainers at sea.
from the body the same level as sea level for the In addition to theoretical knowledge
• Slowly ascend to sea level comfort of the crew and skills, professional divers need
so that nitrogen bubbles do • Oxygen tanks or electrolytic to undergo a series of intensive
not form in the tissues and oxygen generators are provided so training in order for the diver’s body
blood vessels that the oxygen supply is adequate to adapt to extreme pressure.

Figure 2.16 Effects of extreme depth under the surface of the sea

Formative Practice 2.2

1. Explain the existence of atmospheric pressure.
2. The height of the mercury column in a barometer is 756 mm Hg on a cloudy day.
Calculate the atmospheric pressure at that time in pascal.
[Density of mercury, ρ = 13 600 kg m and gravitational acceleration, g = 9.81 m s ]
–2
–3
3. What is the actual pressure at a depth of 125 m in a dam? State your answer in m H O
2
and pascal.
[Atmospheric pressure = 10.3 m H O, density of water, ρ = 1 000 kg m and
–3
2
gravitational acceleration, g = 9.81 m s ]
–2
LS 2.2.4 55