闪卡自测
What is pressure?
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闪卡 1
问题
What is pressure?
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答案
Pressure is defined as the concentration of a force or the force per unit area.
闪卡 2
问题
State the equation relating pressure, force and area.
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答案
The equation for pressure, force and area is Where:
闪卡 3
问题
True or False? Pressure is measured in pascals (Pa).
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答案
True. Pressure is measured in pascals (Pa).
闪卡 4
问题
What is the relationship between force, pressure and surface area?
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答案
A force applied over a large area will result in a small pressure, and vice versa.
闪卡 5
问题
True or False? A high-heeled shoe produces the same pressure on the ground as a flat-soled shoe when worn by the same person.
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答案
False. A high-heeled shoe produces a higher pressure on the ground than a flat-soled shoe when worn by the same person. This is because the same force is applied over a smaller surface area.
闪卡 6
问题
Why do tractors need large tyres?
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答案
Tractors need large tyres to spread their weight over a large area to reduce the pressure they exert on the ground. This prevents them from sinking into the mud.
闪卡 7
问题
What happens when a force is applied to a nail placed against a wall?
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答案
When a force is applied to the nail, it pierces and enters the wall. This is because the applied force is concentrated at the sharp pointed end, which produces a large pressure over a small area.
闪卡 8
问题
True or False? The area used in calculating the pressure should always be the cross-sectional area of the object.
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答案
True. The area used in calculating the pressure should always be the cross-sectional area of the object. This is the area which is perpendicular (90 degrees) to the applied force.
闪卡 9
问题
A box is placed on a table. Calculate the pressure applied by the grey face of the box onto the table.
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答案
The pressure applied by the grey face of the box onto the table is 4 Pa.
闪卡 10
问题
Define a fluid.
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答案
A fluid is either a liquid or a gas.
闪卡 11
问题
How does a liquid exert force on an object suspended in it?
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答案
When an object is suspended in a liquid, it exerts pressure evenly across the whole surface of the object and in all directions. This pressure creates a force which acts at 90 degrees (right angles) to each surface.
闪卡 12
问题
How does increasing depth and density affect the pressure of a liquid?
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答案
The pressure of a liquid increases with both increased depth and increased density of the liquid.
闪卡 13
问题
True or False? The force created by pressure in a liquid is exerted on an object in one direction only.
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答案
False. The force created by pressure in a liquid is exerted evenly across the whole surface of an object.
闪卡 14
问题
State the equation for the pressure difference of an object in a fluid.
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答案
The equation for pressure difference in a fluid is Where:
闪卡 15
问题
State the meaning of in equation . (Extended Tier Only)
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答案
In the pressure equation for liquids represents the change in pressure in pascals (Pa).
闪卡 16
问题
State the meaning of in the equation . (Extended Tier Only)
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答案
in the pressure equation for liquids stands for the density of the liquid, measured in kilograms per metre cubed (kg/m³).
闪卡 17
问题
What quantities are needed to calculate the depth of water in a swimming pool? (Extended Tier Only)
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答案
The depth of water in a swimming pool can be calculated using the pressure equation: The quantities needed to calculate depth are:
闪卡 18
问题
State the property of pressure in a liquid demonstrated in the diagram.
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答案
The property of pressure in a liquid demonstrated in the diagram is that pressure increases with depth.