What is Thrust and Pressure ?
A type of force that affects an object is thrust. There are numerous forces that an object may encounter.
The effect of thrust per unit area on an object is known as pressure, and
the force acting perpendicular to an object’s surface is known as thrust.
An object will experience force when it is kept on a surface. The area of contact with the surface determines how force behaves on it. Less pressure results in a smaller force effect on a larger area, and vice versa for a larger force effect on a smaller area (more pressure).
Thrust Mean
“Perpendicular force is called Thrust .”
The letter “T” stands in for it.
The SI unit of thrust and force are identical. It’s S I unit is newtons (N) = kg m s-2 and C G S unit is dyn = g cm s-2 .
1N = 105 dyne
1Dyn = 10-5 N
It has both magnitude and direction , it is a vector quantity.
Examples of Thrust
An object will lose some weight when submerged in a liquid. This occurs as a result of the liquid pushing up against the object, which reduces the overall downward force. This upward force exerts itself perpendicular to the surface of the submerged object. Up thrust is another name for it.
A force perpendicular to the display board’s surface is used to secure a drawing pin to it.
Definition of Pressure
The thrust acting on an object per unit area is called pressure. The letter “P” stands for it. Assuming that area A is being affected by a thrust T, the pressure applied to the object will be determined by
Pressure = Thrust / Area
P = T / A.
S I unit of Pressure is N /m2 = Pascal (Pa ) = kg m-1s-2 .The letter “Pa” stands for it.
C G S unit of Pressure is Dyn / cm 2 = g cm-1s-2.
1Pascal = 10 dyn /cm2
Define Pascal ?
A pressure of one pascal equals the force of one newton acting on a surface with a surface area of one square metre. 1Pa=1N / 1m2
As a result, 1Pa is equivalent to 1N / m2.
Factors Affecting Pressure
The following elements affect the pressure applied to an object:
a) Surface area in contact: The pressure exerted on an object rises as the surface area on which it is applied falls, and vice versa.
b) The force of the thrust: The thrust acting on an object determines its pressure in a direct proportion. The pressure placed on the object will increase with the amount of thrust.
Examples of Pressure
a) Fruit will be harder to cut if we attempt to cut it with the flat or blunt side of the knife because it will apply less pressure to the fruit’s surface. However, if we use the knife’s sharper side, it will apply more pressure and we can cut the fruit with ease.
b) Because they can have wide soles, camels can easily walk on the sand. They make it easier for them to walk without sinking in the sand because they put less pressure on the sand.
c) To lessen the pressure created by the trains on the ground, wide concrete sleepers are kept beneath the railroad tracks.
d) Wide tyres are used on buses and heavy trucks because they have a larger surface area.
Pressure in a Liquid
Any surface of an object submerged in a liquid is subject to pressure from the liquid. The weight of the liquid column at various liquid heights and the collision of liquid particles in a random motion are the two factors that contribute to the pressure that a liquid exerts. A liquid puts pressure on the walls of the container it is kept in as well as in all other directions. The container’s bottom feels the pressure.
The pressure at a point inside the liquid depends directly on the following three factors:
Depth of the point from the surface of the liquid (h)
Density of the liquid (ρ)
Acceleration due to gravity (g)
Therefore, the pressure inside a liquid, P=hρg.
The pressure inside a liquid does not depend on the shape and size of the container and the surface area on which it is acting.
Pressure Exerted by Air
Air presses down from all sides. The earth’s atmosphere exerts a force on all objects that are on the surface of the planet. Atmospheric pressure is the force generated by the earth’s gravity on the air above the surface. With an increase in altitude from the ground level, atmospheric pressure decreases. A device known as a barometer is used to measure it. In a barometer, the mercury column height reveals the atmospheric pressure. At sea level, the atmosphere exerts a pressure of about 760 mm of mercury.
Difference Between Thrust and Pressure