Pressure exerted by liquids and gases - class-IX

According to Archimedes Principle, the magnitude of buoyant force experienced is equal to the weight of liquid displaced by it by being placed in it.

The property of fluid to exert a buoyant force on an object immersed in it known as Buoyancy .

The given statement is the statement of archimedes principle , so it is true 

$Height=45 cm=0.45 m$,
$gravity=9.8 ms^{-2}$
$Density=1000 kg m^{-3}$
$Pressure=hdg$
$=0.45\times 9.8\times 1000Pa=4410 Pa$.

Second floor :
$P _1=60,000 Pa, g=10 ms^{-2}$
$P _1=h _1dg$

Difference in pressure of water at ground floor and third floor
$=(120000-300000)=900000 Pa$
Density of water $=1000 kg m^{-3}$
Let 'h' be the height third floor.
$P=hdg$
$h=\dfrac {p}{dg}=\dfrac {90000}{1000\times 10}=9m$.

Pressure on the ground floor $=$ Pressure on the first floor + hdg
$\Rightarrow 50000=20000+hdg$
$\Rightarrow 50000=20000+h\times 10^3\times 10$
$\Rightarrow h\times 10^4=50000-20000$
$\Rightarrow h=\frac {30000}{10000}m$
$\Rightarrow height=3 m.$

Vertical length of the alcohol column
$(h)=0.8 m$
Density of alcohol $(d)=0.8 g cm^{-3}$
$=0.8\times 1000=800 kg m^{-3}$
$[\therefore 1 g cm^{-3}=1000 kg m^{-3}]$
$Pressure = hdg$
$=0.8\times 800\times 10$
$=6400 Pa$
Therefore, pressure exerted by the alcohol column is 6400 Pa.

Height $(h)=6 m$,

$Pressure (P)=81600 Pa$
$Density (d)=13.6 g cm^{-3}$
$=13.6\times 1000 kg m^{-3}$
$(\therefore 1 g cm^{-3}=1000 kg m^{-3})$

$Denstiy = 12 kg m^{-3}, Pressure=600 Pa$
$Pressure=hdg$
$\Rightarrow hdg=Pressure\Rightarrow height=\dfrac {P}{dg}$
$=\dfrac {600}{12\times 10}m=5m.$

According to Archimedes' principle, the buoyant force acting on the cube is equal to the weight of the water displaced. Since the cube is resting on the bottom, the total downward force exerted on the bottom of the vessel remains the same because the weight of the water added is balanced by the buoyant force pushing up on the cube.

Every liquid has a density and volume which implies that it has mass & all the bodies having under gravity exerts weight.

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

pressure depends on depth not on area so the two stretched membrane would  have  equal pressure.

Fluids at a given depth exert same pressure in all directions.
Pressure of a liquid is directly proportional to the depth, and for a given depth the liquid exerts the same pressure in all directions according to Pascal's law.

a liquid is  substance that flows freely but is of constant volume, having a consistency like that of water or oil.
The most characteristic feature is volume conserrvation.

According to the law of flotation, a floating object displaces a weight of fluid equal to its own weight. Since the weight of the wooden block is constant regardless of the fluid it floats in, the weight of the displaced fluid must be the same in both river water and ocean water.

$\because p = h\times d\times d$
where, p = pressure
             h = depth
             d = density
so when depth is increases pressure is also increases.

Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same.

Like solids fluids (liquids and gases) also exent pressure. A solid exent pressure only in the downward direction due to its weight, whereas liquids and gases exent pressure on the walls of their container.

Liquid pressure is given by =$\rho \times g \times h$

A fluid is a substance such as liquid or gas which can flow easily, has no fixed shape and can changes its shape at a steady rate when acted upon by a force tending to change its shape.

Density of sea water is more than that of river water. So, at same depth, sea water exerts greater pressure. And, the body of the sea fish is habituated with the high pressure from outside. Now, as the same fish enters the river, water density being low, will suffer less pressure from outside. As a result, the body of the fish will swell out slightly.

Pressure exerted at a point in a liquid is equal in magnitude in all directions, hence it is scalar.

Pressure exerted by the fluids on the sides of the container is called lateral pressure. It depends on the all the given options, mathematically p = hpg

A fluid is a substance that has no fixed shape, can flow easily and yields easily to external pressure, e.g., a gas or  a liquid.

Solid pressure is different from fluid pressure in the sense that solid pressure leads to deformity while fluid pressure doesnt.

Since a fluid has no definite shape, its pressure applies in all directions. Fluid pressure can also be amplified through hydraulic mechanisms and changes with the velocity of the fluid.

 As the pressure exerted by water is directly proportional to the depth of water, as the depth of water increases in a water body, the pressure increases linearly. So when a air bubble rises in water, the pressure acting on the air bubble decreases. 

Different liquids will exert the different pressure at a given depth because of difference in their density.

When the piston is pulled up, air pressure inside syringe reduces because of increase in volume. While pressure outside syringe is more than that. So, it pushes liquid into syringe.

Water pump reduses the pressure at one end of the pipe and pressure difference drives the water to come up from well.

The relationship between liquid pressure and the depth of a liquid:

$\because p = h\times d\times g$
where, p = pressure, h = depth (height), d = density,  g = acceleration due to gravity = constant.

We know that the pressure increases as we go deep into a liquid. The relation is given by $\Delta P = \rho g\Delta h$

A barometer which measures atmospheric pressure most accurately is mercury barometer.

Pressure at any point in the liquid $(P)=hdg$
i.e., $P\alpha h$
(depth of point below the surface)
$\alpha d$ (density of liquid)
$\alpha g$ (acceleration due to gravity)

pressure in a fluid = $\rho gh $ 

Mercury Barometer was invented by Evangelist Torricelli in the year 1643. It is a device used to measure atmospheric pressure.

this is the property of fluid to exert pressure in all directions of a container.

Pressure at a point inside the liquid $(P)=hdg$
Hence, it depends on the depth of the point below the surface of the liquid the acceleration due to gravity at that point and on the nature of the liquid but not on the shape of the containing liquid.

To be able to bear very high pressure of liquid in deep sea.

Submarines.
The hull of Submarines are specially Strengthened to prevent it from collapsing from the high pressure of the water outside while submerged. Roughly every $30$ feet of depth under water adds another atmosphere of inward pressure on the hull.

The pressure at a depth $h$ below the surface of water is given by 

The water in an overhead tank has higher gravitational potential to compared to water which finally flows out of the taps in the houses. 
The water moves due to this decrease in gravitational potential energy of water by flowing out of taps, or, the water is supplied by the gravitational force acting on water.

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid, or, which can easily flow.

The pressure at the bottom of the water surface is