Introduction

 The law simply defines that pressure on a fluid is applied equally on all sides.

Theory

Pascal’s law

Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel. This is Pascal’s law of transmission of fluid pressure, recognized in 1653 A.D. by a French scientist Blaise Pascal (1623-1662).

Discovery of pascal’s law

Pascal's law was discovered during an experiment that was allegedly performed in the 1600's. A 10 m long pole was vertically inserted into a barrel that was filled with water. As the water was poured into the vertical tube, Pascal discovered that the pressure from the water caused the barrel to burst.

As water is poured into the top of the vertical tube, the barrel begins to burst [Figure a].

      Fig: a

Procedures/Methodology

Pascal’s law explanation

According to Pascal’s law, liquid or fluid kept in a closed container, when applied pressure is equally exerted in all the directions no matter the shape of the container. For example; taking a figure as below,

We can see that a force as in the F₁ is exerted into the tube with area A₁ and at the end of the tube there is another opening A₂ which is basically the 10^th times the area A₁. The force F₁ which is applied to the A₁ is equal to the force F₂ in the area A₂.

According to Pascal’s law,

P₁=P₂

Here, A₂>A₁, So,

F₂>F₁.

The force is magnified by the factor A₂ by A₁.

We have always wondered how such big things like cars and heavy objects are lifted, we have an answer for that, it’s simply Pascal’s law. When pressure is exerted on one side of the container where the fluid is kept, on the other side, no matter how heavy the object on the other end is, it can simply be lifted without much effort.

Observation
 

From the theory provided to us and the methodology we used for the experiment to find if the theory is true or not, we have observed that the pressure applied to one opening of the tube is equal to the pressure which is being exerted in the other opening of the tube.

Results/Conclusion

Finding the laws of Pascal to be true, from the experiments we have done. We can finally conclude that the pressure applied to any kind of fluid then the final pressure exerted by the fluid is equal and the force is multiplied with respect to the area of the two ends of the container, the fluid is kept in. Explaining Pascal’s law with its examples:

Application of Pascal’s law:

1.     Hydraulic jack

Hydraulic jack is a device that is constructed on the basis of Pascal’s law. With the help of a hydraulic jack, it is easier to raise a load like trucks, buses, cars, etc. It consists of two pistons of different diameters. When a small effort is applied to the small piston, a large force develops on the larger piston. It is used for servicing automobiles in service centers.

2.     Hydraulic brakes:

Hydraulic brakes are the applications of the Pascal’s law. They are used in heavy automobiles like motorbikes, cars, buses, trucks, airplanes, etc. to stop them by applying a small effort. The construction of hydraulic brakes to multiply effort is as shown in the given figure.

As the brake pedal is pressed, the piston of the master cylinder increases pressure inside the tube containing brake oil. The brake oil transmits pressure equally in all directions. Through the brake oil, pressure spreads to the wheel cylinder. As the wheel cylinder has large cross section area, it magnifies force. Now, the large amount of force is applied on the brake shoes and wheel rim. Finally, the friction between brake shoes and wheel rim slows down the wheel and vehicle stops.

3.      Hydraulic press

Hydraulic press is an application of Pascal’s law. It is used for compressing cotton bales, extracting oil seeds, punching holes in metals, giving specific shapes to metal sheets, etc. The construction of hydraulic press is shown in the given figure. When effort is applied from the force pump, a large force is developed on the large piston. It pushes the load upward. The load is pressed in between piston and rigid ceiling as shown in the given figure.