When body is immersed in a liquid, the liquid exerts an upward force on the body. This force is called the upthrust or buoyant force.
What is upthrust or buoyant force?
The upward force exerted on a body by the fluid in which it is submerged is called the upthrust or buoyant force
Effect of upthrust: It is due to the upthrust that the weight of the body immersed in a liquid appears to be less than its actual weight.
The upthrust has the following two properties
(i) Larger the volume of the body submerged in the liquid, greater is the upthrust.
(ii) More the density of the liquid greater is the upthrust.
Bodies of average density greater than that of liquid, sink in it while bodies of average density smaller than that of liquid float on it.
What is Archimedes’ Principle?
Archimedes’ principle states that when a body is immersed partially or completely in a liquid, it experiences an upthrust, which is equal to the weight of the liquid displaced by it.
What is density?
Te density of a substance is defined as its mass per unit volume.
The relative density of a substance is the ratio the density of the substance to the density of water at 40C.
What is the principle of floatation?
According to the principle of floatation, the weight of a floating substance is equal to the weight of the liquid displaced by its submerged part.
What is a hydrometer?
A hydrometer is an instrument which is used for measuring the relative density of a liquid (heavier or lighter than water) directly and hence to test the purity of a liquid.
The length of the hydrometer immersed is inversely proportional to the density of the liquid in which it is placed.
Showing posts with label fluid. Show all posts
Showing posts with label fluid. Show all posts
Thursday, May 17, 2007
X-revision Pressure in Fluids; Atmospheric Pressure
What is a fluid?
A substance which can flow is called a fluid. All liquids and gases are thus fluids.
What is thrust?
The force acting normally on a surface is called the thrust.
What is pressure?
The thrust on unit area of the surface is called the pressure.
One pascal is defined as the pressure exerted on a surface of area of 1 m2 by a force of 1 N acting normally on it.
A fluid contained in vessel exerts pressure at all points and in all directions.
Total pressure in a liquid at a depth h = Atmospheric pressure + pressure due to liquid column.
What is Pascal’s law?
Pascal’s law states that the pressure exerted anywhere in a confined liquid is transmitted equally and undiminished in all directions throughout the liquid.
What is a barometer?
An instrument used to measure the atmospheric pressure is called a barometer.
Decrease in atmospheric pressure with altitude is due to the following two factors;
(i) decrease in height of air column which produces a linear decrease in the atmospheric pressure.
(ii) decrease in density of air which makes the decrease in atmospheric pressure less rapid.
A substance which can flow is called a fluid. All liquids and gases are thus fluids.
What is thrust?
The force acting normally on a surface is called the thrust.
What is pressure?
The thrust on unit area of the surface is called the pressure.
One pascal is defined as the pressure exerted on a surface of area of 1 m2 by a force of 1 N acting normally on it.
A fluid contained in vessel exerts pressure at all points and in all directions.
Total pressure in a liquid at a depth h = Atmospheric pressure + pressure due to liquid column.
What is Pascal’s law?
Pascal’s law states that the pressure exerted anywhere in a confined liquid is transmitted equally and undiminished in all directions throughout the liquid.
What is a barometer?
An instrument used to measure the atmospheric pressure is called a barometer.
Decrease in atmospheric pressure with altitude is due to the following two factors;
(i) decrease in height of air column which produces a linear decrease in the atmospheric pressure.
(ii) decrease in density of air which makes the decrease in atmospheric pressure less rapid.
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