Pascal's Law Equation
Pascal also wrote about hydrostatics, which explains his experiments using a barometer to explain his theory of the Equilibrium of Fluids, which was not published until a year after his death. His paper on the Liquid Body Equation prompted Simion Stevin to conduct an analysis of the hydrostatic paradox and to correct what is called the last law of hydrostatics:
"That liquid objects distribute compressive power equally in all directions"
which came to be known as Pascal's Law. Pascal's Law is considered important because of the relationship between the Liquid Body Theory and the Gas Body Theory, and about the Changes in Shape about the two which came to be known as the Hydrodynamic Theory. Pascal's Law (1658) "If a liquid is subjected to pressure, then that pressure will propagate in all directions without increasing or decreasing its strength". Pascal's Law states that the pressure exerted by liquid in a confined space is transmitted in all directions equally.
Every point at the same depth has the same amount of pressure. This applies to all liquid substances in any container and does not depend on the shape of the container. If external pressure is added, for example by pressing the surface of the liquid, the pressure increase in the liquid is the same in all directions. So, if given external pressure, every part of liquid gets the same pressure allotment (Lohat, 2008).
In accordance with Pascal's law that the pressure exerted on liquid in a confined space will be transmitted equally in all directions, then the pressure entering the first inhaler is equal to the pressure in the second inhaler (Kanginan, 2007).
Pressure in fluid can be formulated by the equation below.
P = F: A
so that Pascal's law equation can be written as follows.
P1 = P2
F1: A1 = F2: A2
Where: P = pressure (pascal),
F = style (newton),
A = surface area of cross-section (m2).
From Pascal's law it is known that by applying a small force on a vacuum with a small cross-sectional area can produce a large force on a vacuum with a large cross-sectional area (Kanginan, 2007). This principle is utilized in technical equipment that is widely used by humans in life such as hydraulic jacks, hydraulic pumps, and hydraulic brakes (Azizah & Rokhim, 2007).
Principles of Application of Pascal's Law
The Working Principle of Hydraulic Jacks
The working principle of a hydraulic jack is to utilize Pascal's law. Hydraulic jacks consist of two related tubes which have diameters of different sizes. Each is closed and filled with water. The car is placed on the lid of a large diameter tube. If we apply a small force to a tube with a small diameter, the pressure will be spread evenly in all directions including to the large tube where the car is placed (Anonymous, 2009a). If the F1 force is applied to a small suction, the pressure in the liquid will increase with F1 / A1. The upward force exerted by the liquid on the larger suction is this increase in pressure times the area of A2.
If this force is called F2, it is obtained
F2 = (F: A1) x A2
If A2 is much larger than A1, a smaller force (F1) can be used to produce a much larger force (F2) to lift a load placed in a larger suction (Tipler, 1998).
The following is an example of calculating the pressure on a hydraulic jack. For example, a hydraulic jack has two sockets with a cross-sectional area A1 = 5.0 cm2 and a cross-sectional area A2 = 200 cm2. When given an F1 force of 200 newtons, the suction with an A2 cross-sectional area will produce a force F2 = (F1: A1) x A2 = (200: 5) x 200 = 8000 newtons.
Hydraulic Brake Principles Work
The basis of braking work is the use of friction and Pascal's law. The vehicle's motion force will be resisted by this friction force so that the vehicle can stop (Triyanto, 2009). Hydraulic brakes are most widely used in passenger cars and light trucks. Hydraulic brakes using the principle of Pascal's law with pressure on a small piston will be forwarded to a large piston that holds the disc.
Any liquid in the piston can be replaced. Hydraulic brakes are commonly used in brake fluid because the oil can also function to lubricate the piston so that it does not jam (immediately return to its original position if the brake is released). If water is used, it is feared that rusting will occur (Anonymous, 2009).
Hydraulic Brake Principles Work
Hydraulic Pump Operating Principle
In running a particular system or to assist the operation of a system, we often use a hydraulic circuit. For example, to lift a series of containers that have loads of thousands of tons, to facilitate that use a hydraulic system.
Hydraulic system is a technology that utilizes a liquid, usually oil, to make a line of movement or rotation. This system works according to Pascal's principle, that is, if a liquid is subjected to pressure, that pressure will propagate in all directions without increasing or decreasing its strength. The principle in a hydraulic circuit is to use a working fluid in the form of a liquid that is moved by a hydraulic pump to run a particular system (Anonymous, 2009).
The hydraulic pump uses the kinetic energy of the liquid pumped in a column and the energy is given a sudden blow into another form of energy (compressed energy). This pump serves to transfer mechanical energy into hydraulic energy. The hydraulic pump works by sucking oil from the hydraulic tank and pushing it into the hydraulic system in the form of flow (flow). This flow is exploited by turning it into pressure. Pressure is generated by blocking the flow of oil in the hydraulic system.
These obstacles can be caused by orifice, cylinders, hydraulic motors, and actuators. Hydraulic pumps are commonly used there are two types of positive and nonpositive displacement pump (Aziz, 2009). There are two types of equipment that are usually used in converting hydraulic energy into mechanical energy, namely hydraulic motors and actuators. Hydraulic motors transfer hydraulic energy into mechanical energy by utilizing the oil flow in the system to convert it into rotational energy which is used to drive wheels, transmissions, pumps and others (Sanjaya, 2008).