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Questions and Answers
Which type of shoe is likely to exert the greatest pressure on a surface?
Which type of shoe is likely to exert the greatest pressure on a surface?
Flat shoes spread the force over a smaller area, increasing the pressure exerted on the surface.
Flat shoes spread the force over a smaller area, increasing the pressure exerted on the surface.
False
What is the formula used to calculate pressure in fluids?
What is the formula used to calculate pressure in fluids?
pressure = force normal to a surface / area of that surface or p = f ÷ a
The pressure exerted by a fluid is measured in _______.
The pressure exerted by a fluid is measured in _______.
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Match the following shoe types with their pressure characteristics:
Match the following shoe types with their pressure characteristics:
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What happens to pressure in a liquid as depth increases?
What happens to pressure in a liquid as depth increases?
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Upthrust is the force exerted downwards by an object submerged in a liquid.
Upthrust is the force exerted downwards by an object submerged in a liquid.
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What is the density of water in kg/m³?
What is the density of water in kg/m³?
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Pressure is caused by the weight of the column of water above, which is calculated using the formula: Pressure = _______ x depth x gravitational field strength.
Pressure is caused by the weight of the column of water above, which is calculated using the formula: Pressure = _______ x depth x gravitational field strength.
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Match the following depths with the expected pressure at the bottom of a liquid column:
Match the following depths with the expected pressure at the bottom of a liquid column:
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What will happen to an object if the upthrust is greater than its weight?
What will happen to an object if the upthrust is greater than its weight?
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A dam wall is typically shaped like a wedge to manage pressure differences at various depths.
A dam wall is typically shaped like a wedge to manage pressure differences at various depths.
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What is the role of pressure in blood circulation?
What is the role of pressure in blood circulation?
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What happens to atmospheric pressure as altitude increases?
What happens to atmospheric pressure as altitude increases?
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Atmospheric pressure at sea level is approximately 101,000 Pa.
Atmospheric pressure at sea level is approximately 101,000 Pa.
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What are the three important gases in the atmosphere?
What are the three important gases in the atmosphere?
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Aircraft flying at high altitudes must be __________ due to low air pressure.
Aircraft flying at high altitudes must be __________ due to low air pressure.
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Match the following altitudes with their corresponding atmospheric pressures:
Match the following altitudes with their corresponding atmospheric pressures:
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Study Notes
Pressure Calculation
- Pressure is defined as force per unit area. It indicates how a force affects a surface.
Pressure and Shoe Types
- Different shoe types exert different pressures due to variations in their surface area.
- Flat shoes distribute force over a broader area, decreasing pressure. This is useful for walking on soft surfaces like snow, as snowshoes have a large area, significantly reducing pressure on the ground.
- High-heeled shoes concentrate force on a smaller area, leading to increased pressure. This makes stepping on someone's foot in heels more painful than with flats. Similarly, stepping on small objects barefoot increases pressure, intensifying pain.
Pressure in Fluids
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Liquids and gases are fluids.
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Fluid pressure applies a force perpendicular (normal) to a surface.
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The pressure within a fluid can be calculated using the formula:
- Pressure (p) = Force (F) normal to a surface / Area (A) of the surface
- p = F / A
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Units for calculations:
- Pressure (p) is measured in pascals (Pa)
- Force (F) is measured in newtons (N)
- Area (A) is measured in meters squared (m²)
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Pressure in a liquid increases with depth.
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Pressure in a liquid is due to the weight of the water column above.
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Pressure in a liquid acts in all directions.
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Pressure at the bottom of a body of water is greater than at the top.
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Dam walls are wedge-shaped to withstand the increased pressure at the bottom.
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Pressure is essential for life, enabling blood circulation and respiration.
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Every living thing balances with surrounding air or water pressure.
Example Calculation
- A fluid (example given) with 50N force on an area of 2m² has a pressure of 25 Pa (25 pascals).
Further Calculation Example
- A fluid with a 150 N force on an area of 1.2 m² exerts a pressure of 125 Pa.
Pressure in Different Depths
- The pressure exerted by a liquid is calculated using : p = ρgh, where:
- ρ (rho) = density of the liquid (kg/m³)
- g = gravitational field strength (N/kg)
- h = depth (m)
- An object submerged in a liquid experiences a greater pressure on its bottom surface than its top surface. This generates a resultant force upwards.
- This force is called upthrust.
- If upthrust is less than an object's weight, the object sinks.
- If upthrust is greater than an object's weight, the object floats.
Atmospheric Pressure
- The atmosphere is the layer of gases surrounding Earth; key gases include nitrogen, oxygen, and carbon dioxide.
- Atmospheric pressure is caused by air molecules colliding with surfaces.
- Atmospheric pressure at sea level is approximately 101,000 Pa (101 kPa).
- Atmospheric pressure decreases with increasing altitude.
- At the cruising altitude of a passenger plane, atmospheric pressure is about 27,000 Pa (27 kPa).
- Aircraft flying at high altitudes must be pressurized to maintain sufficient oxygen for occupants, as lower pressure limits oxygen intake.
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Description
This quiz explores the concept of pressure, defined as force per unit area, and its application in different contexts such as shoe types and fluids. Learn how different shoes impact pressure distribution and how to calculate fluid pressure using the essential formula. Test your understanding of these principles and their practical implications.
