Fluid Pressure

Slide 1: 

FORCES IN FLUIDS

Slide 2: 

What are fluids? 2. Have you experienced forces in fluids? 3. What is pressure?

Slide 3: 

Why are solids and liquids called fluids? When do you think a gas or a liquid molecule exerts greater push?

Arrangement of Molecules: 

Arrangement of Molecules

Pressure is the push or the force exerted by a molecule over a certain area.: 

Pressure is the push or the force exerted by a molecule over a certain area. F P = A P= pressure F= force A = area

Unit of Pressure: 

Unit of Pressure P=? F= N A= cm2 So, N per cm2

Fluid Pressure: 

Fluid Pressure What is fluid pressure? Fluid pressure is the force exerted by fluids per unit area. The fluid pressure depends on the mass and acceleration of the molecules.

Pressure in our back…,,,,,: 

Pressure in our back…,,,,,

Differences in Pressure: 

Differences in Pressure Drinking in a straw

A Vacuum cleaner: 

A Vacuum cleaner

Slide 14: 

When we inhale, we use the large muscle at the base of our ribcage, diaphragm. It flattens giving the lungs more room to expand. In turn, the air particles inside the lungs has more rooms to move about, which means that the pressure decreases. When the pressure inside the lungs is less than the air pressure outside the body, air is forced through the mouth or nose into the lungs.

Slide 15: 

When we exhale, the diaphragm moves upward, reducing the size of the lungs. This causes the pressure inside the lungs to increase to a pressure greater than that outside the body. The air is forced to come out .

Slide 16: 

Hydraulic Devices Poke this balloon with your finger without popping it, Infer the movement of the air molecules inside .

Slide 17: 

Why can a heavy - fast moving car be stopped right away by single step on its brake?

Transmission of pressure: 

Transmission of pressure ‘How is it possible?

Lifting a hydraulic barber’s chair: 

Lifting a hydraulic barber’s chair Explain how it happens .

Pressure and gravity: 

Pressure and gravity Pool of water

Slide 21: 

Pool of water Weight =1 1 Weight = 1+2 2 Weight= 1+2+3 3 Weight=1+2+3+4 4 Weight=1+2+3+4+5 5 G R A V I T y

Slide 22: 

The increase in pressure is associated with an increase in depth.

Our planet is surrounded by fluid atmosphere……: 

Our planet is surrounded by fluid atmosphere……

Slide 24: 

The higher the altitude the lower the pressure

BUOYANCY: 

BUOYANCY Why a heavy object appears to be weigh less in water than on land?

Slide 26: 

The force at the bottom of an object in a fluid is greater than the force at the top of the object The overall force is in the upward direction and acts against the downward weight f the object. The upward fore is called buoyant force That is buoyancy

Slide 27: 

Exactly, the phenomenon is buoyancy, the reason why an object seems weigh less on water.

You in a bathtub…………: 

You in a bathtub………… What happens to the level of water when this women stepped inside the bathtub?

Have you ever heard tip of the iceberg: 

Have you ever heard tip of the iceberg

Slide 30: 

Wonder why a steel ships float in water

Slide 31: 

FLUIDS IN MOTION Get a long, thin strip of paper. 1.Get a long, thin strip of paper. 2. Put the paper in a book by inserting about 5cm of it between two pages. 3. Hold the book upright in front of your mouth so that paper hangs over the far side of the book.

Airplane pix here: 

Airplane pix here How does it make the world smaller?

Kite flying: 

Kite flying