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Fluid Dynamics of Pressure:
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- Definition: Pressure measures the amount of force applied per unit area.
- It’s calculated as Pressure = thrust/area.
- Unit: The SI unit of pressure is Pascal (Pa), which is equivalent to N/M2 or Nm-2.
- Named after the French mathematician and physicist, Blaise Pascal.
- Concept: Pressure depends on the amount of thrust and the area over which it is distributed.
- If you exert the same force (or thrust) over a smaller area, the pressure is greater and vice-versa.
- Further Interpretations:
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- Situation 1: When fixing a poster using drawing pins, the force applied by your thumb on the pin’s head is spread out on its broader end but focuses on a much tinier area at its pointed tip.
- Situation 2: Standing versus lying on loose sand presents different outcomes because of pressure distribution.
- Standing makes your feet sink due to the force (your weight) acting on the smaller area of your feet.
- Conversely, when lying down, the same force spreads over a larger contact area, which means less sinking.
- Real-life Applications:
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- Camel’s Feet: A camel can walk on desert sand without sinking because its feet are wide. This distributes the camel’s weight over a larger area, reducing the pressure on the sand.
- Tank stability: Role of continuous chains in weight distribution: A tank uses a continuous chain to distribute its heavy weight over a large surface area, reducing the pressure on the ground and preventing it from sinking in.
- Wide Tires in Heavy Vehicles: Trucks and buses have wide tires to distribute their heavy weight over a larger surface area, thereby reducing the pressure on roads.
- Sharp Tools utilize Pressure for cutting and piercing: Cutting tools like knives and needles have sharp edges or points to concentrate the force over a very tiny area, producing a large pressure that can easily cut or pierce materials.
- Nail Penetration Dynamics: The Power of Force and Precision: The pointed end of a nail can more easily penetrate a wooden plank than its head, indicating that the same amount of force applied over a smaller area results in a greater effect.
- Porters Carrying Load and the Art of Weight Distribution: Porters place a round piece of cloth on their heads, when they have to carry heavy loads.
- By doing this they increase the area of contact of the load with their head.
- So, the pressure on their head is reduced and they find it easier to carry the load.
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