Question

Question 3: Explain pressure. ( it is advised to look at the supplied materials and explain from them)

Supplied Materials:

-For static fluids, consider the force balance. Fluid statics.
is there. In the case of liquids, the change in pressure due to height is large, and it must be handled. Also, even when the container is in a relatively stationary state, for example, when the container is operating at high speed, it is possible to think of the motion of the fluid in the target system fixed to the container as if it were the stationary fluid.
  

3.1 Pressure p.22~

p expressed as p=P/A is called Pressure and P is called total pressure. When the pressure is not uniform, the pressure at one point is p=lim ΔA→0 (ΔP/ΔA)=dP/dA
Is displayed.

3.1.1 Unit of pressure p.22~
・In SI unit, the unit of pressure is often expressed as Pascal (Pa) or Bar (bar) or Water column meter (mH2O, mAq). Refer to Table 3.1 on page 23 of the textbook for pressure unit conversion. Of these, remember the following three in particular. 1Pa=1N/m2
1atm=101325Pa
1mHg=1/0.76atm
Pa is the basic unit of pressure, atm is 1 atm, and 1 mHg is used for conversion when measuring mercury column.

3.1.2 Absolute pressure and gauge pressure p.23~
・There are the following two methods to express the pressure. Be careful not to be confused.
(See Figure 3.1 in textbook p.23.) Absolute pressure: A method based on perfect vacuum. Gauge pressure: A method based on atmospheric pressure. (Gauge pressure) = (Absolute pressure)-(Atmospheric pressure) In other words, the gauge pressure indicates whether or not there is a pressure difference from atmospheric pressure. Therefore, the pressure measuring instrument usually shows gauge pressure, so it is necessary to consider the atmospheric pressure.

3.1.3 Properties of pressure p.23~
・Pressure has the following three properties. (1) The pressure of the fluid always acts vertically on the wall surface in contact with the fluid. (2) The pressure at one point in the stationary fluid is the same in both directions. (3) The pressure applied to the fluid in the closed container is transmitted to all parts with the same strength. Pascal principle: F2/A2 = F1/A1
∴ F2 = F1 × (A2/A1)

End of supplied materials. Thank you so much, and I hope you are able to deliver this. The explaination shouldnt be short but not too long either is thats not a bother

Answer 1

Static pressure - It is mainly because of the height at which fluid is stored this is because of potential energy stored in a body (mgh).

The pressure is also defined as a force per unit area. It has units like Bar, pascal, in terms of the head also like water head, mercury head

Our atmospheric pressure is 1bar or
101.325Kpa or
10.3 m of water head, or
760 mm of mercury

Unit conversitions
1bar =10^5 Pa = 10^5 N/m

Absolute pressure- It is a pressure reading in which atmospheric pressure is added or already included.

Gauge pressure - It is pressure reading in which atmospheric pressure is not added or we exclude that.

The relation between gauge pressure absolute pressure

Gauge pressure = Absolute pressure - atmospheric pressure

Vacuum pressure -Any pressure less than atmospheric pressure is known as vacuum pressure

Properties:-
1) pressure always acts vertically because its value varies with height, in a fluid containing all will feel less pressure at the upper side while it will feel high resin lower side.

2) The pressure at one point in a fluid is same in all direction this is so to balance all the forces acting on a particle so that there will be no shear between fluid layer and fluid will be staying in rest

3) Again to balance the forces on all the liquid particles the pressure applied to fluid distributed equally

Pascal's law- pressure applied to a point in a fluid is equal in all direction
This phenomenon is widely used in a hydraulic machine to lift heavy objects by applying less force.
As pressure is to remain constant at every point in a fluid
F1/A1= F2/A2

I hope now you will understand and concept of pressure is crystal clear to you, please let me know of any more help you need.

Please rate positively