## Physics: Darasi akan pressure in fluid

• Ga definition na pressure a Turance kamar haka; pressure is defined as the force acting perpendicularly per unit area.

Idan kuma za a duba equation na shi ne a math, shi kuma ga shi kamar haka:

Pressure = Force / Area , shi ne kamar haka,  P = F / A

Ga abinda ko wani harafi ke nufi kamar haka:

1. P = pressure
2. F =Force
3. A = area
4. F/A = F divide by A

Pressure due to gravity

Ga kuma bayanin pressure due to gravity kamar haka a Turance:

Since the weight of an object or material is equal to the force it exerts due to gravity, an object can exert down ward pressure due to its weight and the force of gravity. The pressure you exert on the floor is your weight divided by the area of the soles of your  shoes. If the force is due to the weight of the object, the equation is then,

Pressure = Weight / Area, shi ne haka , P = W / A

Abinda ya kamata mu sani, F = W = mg, inda m  shi ne mass (kg) sai kuma g shi ne acceleration due to gravity (m/s). Ana gwada pressure ne da Nm-2. 105Nm-2 = 105Pa = 1bar.

Bayan bayanan da suka wuce, yanzu za mu dauki misalai don ganin yadda ake amfani da su. Zamu amsa tambayoyi ne da ke fitowa a jarabawar karshen aji shidda na sakandire wato ( NECO,  WAEC,JAMB). Zamu yi amfani da fomula pressure domin amsa tambayoyin.

Za a iya duba: Takaitaccen bayani game da gravitational field

Misali na daya:

A rectangular water tank of weight 4.5 � 10N measures 2.0m by 1.5m by 1.2m. Calculate the minimum pressure it can exert when resting on a horizontal surface.    NECO 2006.

Amsar Tambaya:

Minimum pressure is obtained when the tank rest on the greatest area.

From , 2.0m by 1.5m by 1.2m the greatest area , A = 2 � 1.5 = 3.0m2

Weigh, W = F = 4.5 � 103N

Pressure = F / A = 4.5 � 103 / 3.0 = 1.5 � 103Nm-2

Misali na biyu:

A rectangular block of dimensions 2.0m � 1.0m � 0.5m weigh 200N. Calculate the maximum pressure exerted by the block on a horizontal floor.     WAEC 2008

Amsar tambaya:

Maximum pressure is obtained when the block rest on the least area.

From �2.0m � 1.0m � 0.5m�� the least area, A = 1.0m � 0.5m = 0.5m2

Weight of block W = F = 200N

Therefore, pressure exerted P = F / A = 200N / 0.5 = 400Nm

Misali na uku:

A rectangular tank contains water to depth of 2m. if base is 4m � 3m calculate the force on the base. (Density of water = 103kgm-3, g = 10ms-2 ).   A. 2.4 � 10                  N  B.2.4�10 C.2.0 � 10N  D.1.7 � 103N                 JAMB 1986

Amsar tambaya:

Force din da ya ke a base na tank zai dogara ne akan weigh ( W ) na ruwan.

Volume of tank = 4� 3 � 2 = 24m3

Density of water = 1000kgm-3

Density = mass / volume, therefore, mass of water, m = density � volume

m = 1000 � 24 = 24000kg

weight of water, W = F = mg = 24000 � 10 = 2.4 � 10N

Fluid pressure

A Turance, fluid pressure (by Ron Kurtus ,revised 8 may 2017) is a measurement  of the force per unit area on an object in fluid or on the surface of closed container. This pressure can be caused by gravity, acceleration, or by forces outside a closed container. Tun da shi fluid

(abu mai ruwa-ruwa) ba shi da wani definite shape, don haka pressure dinsa yana applying a kowanne direction. Fluid pressure can also be amplified through hydraulic mechanisms and changes in the velocity of the fluid.

Pressure a cikin fluids (liquids ko kuma gasses) ya danganta ne da depth ko zurfi ko height wato tudu da kuma density na fluid din. Ga fomulolin fluid pressure kamar haka, sunanan kamar daba-daban. Ga su kamar haka:

P = F / A

P = mg / A

P = ? � V � g

P = ? � A � h � g / A

P = ?hg

Where P = pressure ( Nm-2 ),

m = mass ( kg)

A = area (m)

h = height or depth (m)

F = force g = acceleration due to gravity (m / s2)

? = density (kgm-3)

Tunda mun ga formulas daban-daban wanda ake amfani da su a fluid pressure, yanzu za mu dauki misalai wanda zamu yi amfani da wadannan fomulolin domin mu amsa tambayoyin.

Misali na uku:

A reservoir is filled with a liquid of destiny 2000kgm-3. Calculate the depth at which the pressure in the liquid will be equal to 9100Nm-2. (g = 10m/s)  WAEC 2002

Amsar tambaya:

Density of liquid, ? = 2000kgm-3; pressure, P = 9100Nm-2; g = 10m/s2

P = ?hg, therefore, depth, h = p / ?g   = 9100 / 2000 � 10 = 0.455m

Misali na hudu:

A 5m � 4m � 3m vessel of negligible weight is filled with a liquid of density 2500kgm-3  if the vessel is placed on a flat surface, what is the maximum pressure it can exert?

Amsar tambaya:

The maximum pressure is exerted when the vessel rests on its least area.

From 5m � 4m � 3m, the least area, A = 4 � 3 = 12m2

Volume of vessel, V = 5 � 4 � 3 = 60m3

Density of liquid ? = 2500kgm-3

Yanzu zamu dauka daga, ? = m / v, mass, m = ? � V = 2500 � 60 = 150000kg

W = F = mg = 1.5 � 105kg � 10 = 1.5 � 10N

P = E / A = 1.5 � 106N / 12 = 12500 = 1.2 � 10N/m2

Alternatively, zamu iya applying formula pressure, P = ?hg  saboda pressure a cikin liquid ya na depending ne da height ko depth. If the vessel rests on its least area 4 � 3, then the height (h) becomes 5m.

P = ?hg = 2500 � 5 � 10 = 1.25 � 10N/m2

Ga wannan makalar da ta yi bayani game da charle's law, za ku iya dubawa.

Da wadannan misalan na kawo karshen wannan makala. Kamar yadda na ke fada a kullum, yana da kyau ku kara bincike sosai ko ku duba wasu textbooks na physics tare da duba wasu tambayoyin da ke fitowa a jarabawar karshen gama sakandire akan wannan darasi na pressure fluid. Ku yi kokarin gwada amsa su tare da fomulolin da muka baku na fluid pressure don karin fahimtar wannan maudu�i.