Basic fluid mechanics

By -

What is matter?
Matter has following properties
1. occupies space 
2. All things are made of because . 
3. Matters have mass.

What is mass?

Mass is a measure of the quantity of matter in an object. Mass determines inertia of matter. To be more specific the mass depends purely on the intensity of atoms present in the object. Atoms have electrons,protons and Neutrons.

What is weight?
Whatever may be the intensity of mass (whether it is heavy or light), that mass will be attracted by bigger mass, Earth.Biggest mass in the universe is Sun. If you refer universal law of gravitation, you will find the physics behind it that is Bigger mass always attracts lesser mass. The attraction force depends upon the distance between objects in interest. When mass is attracted by some vector like gravitational force, it also becomes a vector and that vector is called as Weight.

                     Weight = mass x acceleration due to gravity

Why astronauts are freely falling on space though they have mass?
Mass won't change with respect to its position on universe. But weight can differ since because of acceleration due to gravity of earth decreases when the altitude that is height increases. This is the reason for astronauts free fall in space.

Comments

Post a Comment

Popular posts from this blog

Fire detection system in aircraft

By -
Image
What are the common fire detection methods followed in aircraft? Explain them with neat diagrams. Thermal Switch: Thermal switches are heat –sensitive units that complete electrical circuits at a certain temperature. They are connected in parallel with each other. If the temperature rises above a set value in any one section of the circuit, the thermal switch will close the electrical circuit and gives indication to the pilot through indication lights. Thermo-couple systems: A thermocouple gives the rate of temperature rise. A Thermocouple is the junction of two dissimilar metals which generates a small electric current that varies according to the temperature of the junction. For this reason it does not require an external power source. The dissimilar metals can be constantan and iron, Alumel and Chromel, or some other combination of metals or alloys which will produce the required results. The complete thermocouple circuit consists of the ‘cold’ junction, the ‘h...
Get more »

Vapour cycle cooling system in aircraft

By -
Image
Explain the vapor cycle cooling system used in aircraft with neat illustration. Also explain the physics behind the scene of working. Physical principle Liquids can be vaporized at any temperature by changing the pressure acting on it.  To clearly understand this concept, we will take an example of water contained in a vessel. When the vessel is at atmospheric pressure, the water will be boiling at 100°C when heating. If I am pressurizing the vessel to more than the atmospheric pressure, then water will not boil at 100°C. If I am creating a drop in pressure in the vessel by a vacuum pump, then water will boil at a temperature less than 100°C. Basic law of thermodynamics states that heat will always flow from hot body to cold body. If I need a reverse of this, I have to add some work. System operation: 1. We are having the FREON as refrigerant in the vapor cycle cooling system. It has a boiling point of 4°C. 2. At the receiver I am having high pressure, ...
Get more »

Stall- Stagnation point- Parts of aircraft- Critical angle of attack

By -
Image
What are the major parts of an aircraft? Main wing Tail wing Powerplant Fuselage Landing gear What is the reason for stall? Define critical angle of attack? If the angle of attack for an aerofoil increases from zero deg, you can watch the increase in lift and drag. If you keep on increasing the AOA, at some point sudden loss of aerodynamic forces will occur. Aerofoil can create aerodynamic forces in a large magnitude when attached flow of air occurs at aerofoil surface.  As the aerofoil gets increased AOA, the flow of air starts detaching from the aerofoil surface. If fully detached then no aerodynamic forces will be generated. That is what the reason for stall. The angle at which stalling starts is the critical angle of attack. What is stagnation point? Stagnation point is the point in the airflow where the velocity gets its zero magnitude because of the presence of object in airflow. The flow deviates/joins between upper and lower surface of the ...
Get more »