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Pressure and Archimedes’ Principle

Pressure and Archimedes’ Principle: Weight, Thrust and Pressure, Buoyancy,, Relative Density and Archimedes’ Principle experiment etc.

Pressure and Archimedes’ Principle: Introduction

Weight: 

  • The earth attracts everything with a special force and this force depends on the velocity due to the mass (m) and gravity (g) of the object
  • The weight of an object is defined as the force, by which it is attracted towards the earth
  • It is denoted by W

W = m × g

  • The SI unit of weight is equal to the force, i.e. Newton (N)
  • The weight is a force that acts vertically downwards and has both magnitude and direction
  • Weight depends on its location because the value g  depends on its location

Thrust and Pressure:

  • Thrust: It is the force acting on an object perpendicular to the surface. The effect of the force depends on the area in which it operates
  • Pressure: The thrust on the unit area is called pressure

Pressure = Thrust Area

  • The SI unit of pressure is N/m2 or also written as  N m–2
  • The SI unit of pressure is called Pascal (Pa) and it is in the honor of scientist Blaise Pascal
  • The same force acting on a smaller area exerts a larger pressure, and a smaller pressure on a larger area and vice versa follow for pressure
  • Therefore, a nail has a pointed tip, knife edges are sharp and the foundations of buildings are wide

Pressure in fluids:

All liquids and gases are liquids. Like solids, fluids carry weight and they also exert pressure on the base and walls of the container in which they are enclosed. The pressure applied by any limited mass of liquid is transferred in all directions without any reduction.

Buoyancy:

The force exerted by water on an object is called the force of force or the force of pleasure.

  • When they are immersed in a liquid, all objects experience a pleasant force
  • The intensity of this pleasing force depends on the density of the fluid
  • Objects with a lower density than liquids float on the liquid. For example, cork
  • Objects with a denser than liquid sink into the liquid. For example, nails

Archimedes’ Principle:

It states that “when a body is completely or partially immersed in a fluid, it experiences an upward force equal to the weight of the fluid which is displaced by it.” Here are some of its applications:

  • It has large applications such as it is used to design ships and submarines. 
  • Lactometers (decide the virtue of an example of milk) and Hydrometers (decide the thickness of fluids) depend on this guideline.

Archimedes worked in the field of Geometry and Mechanics. His understanding of levers, pulleys, wheels and axles helped the Greek army in its war with the Roman army.

Relative Density:

  • Density: It is defined as the mass of a unit volume of a substance
  • SI unit of density is kilogram per meter cube or simply written as (kg m–3)
  • The density of a substance, under certain conditions, remains the same
  • It is different for different substances.
  • Relative Density: It is characterized as the proportion of the thickness of a substance as for that of water

Relative density = The density of a substanceDensity of water

  • Relative density does not have any unit as is a ratio of similar quantities.

Archimedes’ Principle Experiment

You can experiment Archimedes’ Principle by following the below method:

First, you need to take a water filled container to the brim. Now, you need to take a solid object and then measure its weight  using a spring balance. Now, keep the object attached to the spring balance and then you need to submerge it in water. Note that the spring balance is not submerged. Check the weight shown by the spring balance. You will see that it is less.Few amount of water will be displaced into the bowl. Collect and then measure the weight of the water. You can see that the water weight will be exactly proportional to the loss of the weight of the object.

Conclusion

In this article we have learned about the concept of pressure and Archimedes’ Principle.Archimedes worked in the field of Geometry and Mechanics. His understanding of levers, pulleys, wheel sand-axle helped the Greek army in its war with the Roman army.According to Archimedes’ Principle,  “when a body is completely or partially immersed in a fluid, it experiences an upward force equal to the weight of the fluid which is displaced by it.” Like solids, fluids carry weight and they also exert pressure on the base and walls of the container in which they are enclosed.Archimedes’ Principle  has large applications such as it is used to design ships and submarines.  It is also used in Lactometers (decide the virtue of an example of milk) and Hydrometers (decide the thickness of fluids) depending on this guideline.