Statics and dynamics of fluid (liquid and gas) - class-IX

 pressure at a point in a fluid is = $\rho gh $ where $\rho$ is the density of the liquid , h is the height or depth of the object from the surface , so pressure increases with increase in depth so given statement is false .

 1 atm = 1 pa = 76 cm of Hg 

Pressure exerted sideways is known as  lateral pressure  , hence the given statement is true so option (A) is correct

With the increase in the weight of an object the pressure increases because pressure is thrust per unit area.

$Load=900 kgf, Effort (E)=?$
Area of cross section of the press plunger $=a _1=9 m^2$
Area of cross - section of the pump plunger $=a _2=0.03 m^2$
By Pascal's law,
Pressure exerted by pump plunger $=$ pressure exerted on press plunger.
i.e., $\displaystyle \frac {L}{E}=\frac {a _1}{a _2}\Rightarrow \frac {900 kgf}{E}=\frac {9 m^2}{0.03 m^2}$
$\displaystyle \Rightarrow E=\frac {900 kgf\times 0.03 m^2}{9 m^2}=3 kgf$.

Force $(F)=500000 N$
$Pressure=250000 Pa, Area (A)=?$
$A=\frac {F}{P}=\frac {500000}{2500000}m^2=0.2m^2$.

To maintain normal atmospheric pressure below sealevel, deep seadivers wear a special suit.

Pressure is expressed as force per unit area

Pressure is a scalar quantity, not a vector quantity. It has a magnitude but no direction associated with it. Pressure acts in all directions at a point inside a gas. At the surface of a gas, the pressure force acts perpendicular to the surface.

For example. one that does not appear to move or flow. While the gas as a whole does not appear to move, the individual molecules of the gas, which we cannot see, are in constant random motion. Because we are dealing with a nearly infinite number of molecules and because the motion of the individual molecules is random in every direction, we do not detect any motion. If we enclose the gas within a container, we detect a pressure in the gas from the molecules colliding with the walls of our container. We can put the walls of our container anywhere inside the gas, and the force per area (the pressure) is the same. We can shrink the size of our "container" down to an infinitely small point, and the pressure has a single value at that point.

Therefore, it is false. 

Hydrostatic pressure at a given depth depends only on the density of the liquid, gravity, and the depth (P = rhogh). It is independent of the surface area of the object.

Force on mesh = change in momentum per unit time. 50% pass through (no change), 25% stop (delta p = mv), 25% rebound (delta p = 2mv). Total force = 0.25(mv) + 0.25(2mv) = 0.75mv. Pressure = Force/Area = 0.75 * rho * v^2.

Answer is B.

Pressure is defined as force per unit area. It is usually more convenient to use pressure rather than force to describe the influences upon fluid behavior. The standard unit for pressure is the Pascal, which is a Newton per square meter.
Therefore, pressure is a scalar quantity, not a vector quantity. It has magnitude but no direction sense associated with it. Pressure acts in all directions at a point inside.
Hence, the statement is false.

Answer is B.

Varying air pressures in buildings result from uncontrolled air flow patterns.When a space is under a positive air pressure, indoor air will be pushed outward in the walls, floor and ceiling. When a space is under a negative pressure, air will be pulled inward through the walls, floor and ceiling. 
In this case, the windows in the room are open and so there is free flow of air in and out of the room. 
Hence, air pressure is nearly the same on the floor, the walls and ceiling.

Water flowing in the river is comprised of kinetic energy and potential energy. In hydroelectric power plants the potential energy of water is utilized to produce electricity.

Pascal is the S.I. unit of pressure. So, the pressure is measured in the unit pascal.

pressure is a scalar quantoty as it does not have any direction.

1 millibar = $10^{-3} bar$

pascal is the SI unit of pressure

$Pressure=\dfrac{Force}{Area}=\dfrac{Force \times Distance}{Area \times Distance}=\dfrac{Work}{Volume}$

$Pressure=\dfrac{Force}{Area}$

$Pressure=\frac{Force}{Area}=\frac{Force \times Distance}{Area \times Distance}=\frac{Work}{Volume}$

Unit of Pressure, $Pa$ (in SI) is derived from the units of Force ($N$ in SI) and Area ($m^2$ in SI).
$Pa=\dfrac{N}{m^2}$
So, it is a derived unit.

$Pressure=\dfrac{Force}{Area}=Constant$

With the increase in temperature, the density of atmosphere decreases, hence the atmospheric pressure decreases.

Pressure is defined as force per unit area. The standard unit for pressure is the Pascal, which is a Newton per square meter.

$P=\dfrac{F}{A}$

Here the force acts perpendicularly on the area. 

Pressure is a measure of effect of force on an object.

Pressure can be defined as force per unit area i.e. $\dfrac{Force}{Area}$. 

The atmospheric pressure exists due to weight of the atmosphere above it. 
As the altitude increases, the amount of atmosphere above, and hence its weight, and hence the atmospheric pressure decreases.

We know that pressure is the force per unit area. 

Force = change in momentum per second. For one ball, delta p = 2mv. For 1000 balls, F = 1000 * 2 * (0.001 kg) * (100 m/s) = 200 N. Area = 1 cm^2 = 10^-4 m^2. Pressure = 200 / 10^-4 = 2 * 10^6 N/m^2.

(A) if we decrease the area of the ice skating blades, then we mean to say we are increasing the pressure. We actually do this to increase pressure which reduces the chances of getting slipped.

(a) Pressure is same at all points in the horizontal plane. (correct)
(b) A liquid seeks its own level. (correct)
(c) The lateral pressure exerted by a liquid decreases with the increase in depth of the liquid. (wrong)
(d) The upper surface of a stationary liquid is always horizontal. (correct)

For AB <=> A + B, let initial moles be 1. At equilibrium: AB (1-x), A (x), B (x). Total moles = 1+x. Partial pressures: P_AB = (1-x)/(1+x) * P_total, P_A = x/(1+x) * P_total, P_B = x/(1+x) * P_total. Kp = x^2 / (1-x^2) * P_total. Given Kp = 4 * P_total, so x^2 / (1-x^2) = 4. x^2 = 4 - 4x^2 => 5x^2 = 4 => x^2 = 0.8 => x = 0.894, approx 0.9.

$\begin{array}{l} PV=nRT \ P\propto T \ \therefore , { T _{ A } }>{ T _{ B } }>{ T _{ C } } \ So, \ { P _{ A } }>{ P _{ B } }>{ P _{ C } } \ Hence, \ option, , A, , iscorrect, answer. \end{array}$

Given,

$W = nR\Delta T$

$\begin{array}{l} Given, , { P _{ 1 } }=200, , k, pa \ { T _{ 1 } }=22^{ \circ  }C=273+22-295K \ { T _{ 2 } }=42^{ \circ  }C=273+42=315K \ PV=nRT \ \left( { \dfrac { { PV } }{ T }  } \right) ={ { constant } }\left[ \begin{array}{l} { { Since } }, , number, , of, , moles \ and, , R, , are, , { { constant } } \end{array} \right]  \ \dfrac { { { P _{ 1 } }{ V _{ 1 } } } }{ { { T _{ 1 } } } } =\dfrac { { { P _{ 2 } }{ V _{ 2 } } } }{ { { T _{ 2 } } } }  \ \dfrac { { 200\times 1 } }{ { 295 } } =\dfrac { { { P _{ 2 } }\left( { 1.02 } \right)  } }{ { 315 } }  \ { P _{ 2 } }=\dfrac { { 200\times 315 } }{ { 295\times 1.02 } } , , kPa \ = 209, , kPa \end{array}$

A pressure wave undergoes a phase change of $ \pi$ radians on 

The pressure is the force per unit area. So, $P=F/A$

Pressure is defined as force applied per unit area. Hence, its SI unit is $N/{ m }^{ 2 }$ or Pascal here,

Pressure(P)$=$$ \frac{Force(F)}{Area(A)}$

As both the women have same weight, so both of them will apply the same force on the ground. But flat soles having larger area compared to sandals with pointed heels, will exert lesser pressure compared to that of sandals having pointed heels. So, the sandals with pointed heels will sink more. Therefore, the woman having flat sole sandal will feel more comfortable while walking on a sandy beach.

Pressure is defined as force per unit area. The standard unit for pressure is the Pascal, which is a Newton per square meter.

$P=\dfrac{F}{A}$

For an object sitting on a surface, the force pressing on the surface is the weight of the object, but in different orientations it might have a different area in contact with the surface and therefore exert a different pressure.

pressure acting sideways is known as lateral pressure .

Pressure can be defined as the force per unit area which can be written as $\dfrac{Force}{Area}$.

Although Force and Area, both are vector quantities, pressure is a scalar quantity.

Pressure affects substances in al the state whether it is liquid, solid or gaseous.

Pressure is the force acting on a unit area of a surface it can be written as pressure  $= \dfrac{force}{area}$

Pressure is force acting on a unit area of a surface when force applied on object in a particular area of object exert pressure on it.

When a force acts vertically downwards or normal to the surface under consideration, it is called thrust.