Presentation on theme: " In order to calculate pressure exerted on a surface, what quantity is divided by the surface area force."— Presentation transcript:
In order to calculate pressure exerted on a surface, what quantity is divided by the surface area force
What is the SI unit of pressure? the pascal
A pressure of 70 N/m 2 equals 70 Pa.
Which of the following materials is NOT a fluid? › air › gasoline › cork › Water Cork
If the air inside a balloon exerts a force of 1.5 N on an area of 0.5 m 2, what is the pressure inside the balloon? 3 N/m 2
Atmospheric pressure is caused by the weight of the atmosphere above a particular location.
The pressure of air at sea level is approximately 101 kPa.
According to Bernoulli’s principle, is the fertilizer solution in Figure 13-2 pulled or pushed up the tube (B)? The solution is pushed up the tube because of the pressure difference
Which principle states that a change in the pressure at any point in a fluid in a closed container is transmitted equally and unchanged in all directions throughout the fluid? Pascal’s principle
Where is fluid pressure greatest? › A.30 centimeters below the surface of a swimming pool › B.1 meter below the surface of a swimming pool › C.2 meters below the surface of a swimming pool › D.The pressure is the same in all parts of a swimming pool. 2 meters below the surface of a swimming pool
The operation of a hydraulic lift system is explained by Pascal’s principle.
Where will the greatest increase in pressure occur if you squeeze the middle of an upright, closed soft-drink bottle? The pressure will increase equally everywhere within the bottle.
The hydraulic system of a dump truck is designed to multiply force.
State Bernoulli’s principle. As the speed of a fluid increases, the pressure within the fluid decreases.
A cork is floating in salty water. As more salt is added to the water to increase its density, the cork will Float at a higher level
The upward force acting on the wing of an airplane in flight is called lift
Which of the following statements is true about an airplane wing during flight? › A.Air above the wing travels faster than air below the wing. › B.Air below the wing travels faster than air above the wing. › C.The wing exerts pressure equally in all directions. › D.The lift acting on the wing reduces the weight of the wing. AA
The upward force acting on an object submerged in a fluid is called Buoyant force
The SI unit of pressure is the Pascal
The strength of the buoyant force acting on an object in a fluid depends on the object’s volume.
A ball is floating partially submerged in a liquid. The buoyant force acting on the ball equals the volume of the ball below the surface.
Which of the following substances will float in corn syrup? (The density of corn syrup is 1.38 g/cm 3.) › copper (8.9 g/cm 3 ) › iron (7.8 g/cm 3 ) › silver (10.5 g/cm 3 ) › glycerin (1.26 g/cm 3 ) glycerin (1.26 g/cm 3 )
The buoyant force on an object in a fluid is equal to the weight of the fluid displaced by the object.
The formula Force/Area is used to calculate Pressure
Two identical corks float in separate beakers. One beaker contains distilled water. The other contains very salty water. Which of the following statements is true? › A.The corks float at the same level in both liquids. › B.The cork in the very salty water floats at a lower level than the other cork. › C.The corks will eventually sink. › D.Both corks are subject to the same buoyant force. D.Both corks are subject to the same buoyant force.
In this picture, spheres of which color have the greatest density? Black
A substance that flows and assumes the shape of its container is a(an) Fluid
Why does a hot-air balloon float? › A.The shape of the balloon provides lift. › B.The volume of the air displaced by the balloon is less than the volume of the balloon. › C.The weight of the air displaced is less than the volume of the balloon. › D.The weight of the balloon is less than the weight of the air displaced by the balloon. D.The weight of the balloon is less than the weight of the air displaced by the balloon.
The pressure exerted by a fluid at any given depth is exerted ____________________ in all directions. Equally
As your altitude increases, air pressure Decreases
A hydraulic jack is an application of ____________________ principle. Pascal’s
A device that uses pressurized fluids acting on pistons of different sizes to change a force is called a(an) Hydraulic system
Even a rock at the bottom of a lake has a(an) ____________________ force acting upward on it. Buoyant
As the speed of a fluid increases, the ____________________ within the fluid decreases. Pressure
In a hydraulic lift system, the fluid pressure exerted throughout the system is Constant
The downward force produced when air flows over the winglike spoiler on a race car is an example of ____________________ principle. Bernoulli’s
The direction of the buoyant force on an object placed in a fluid is Upward
The unit g/cm 3 is often used to express Density
As you climb a high mountain, the buoyant force exerted on you by the atmosphere Decreases
A submerged submarine alters its ____________________ to rise or fall in the water. Density
Which exerts greater pressure on the floor—standing flat-footed or standing on tiptoes Standing on tiptoes
The apparent loss of weight of an object in a fluid is called Buoyancy
How do the particles of a liquid exert pressure on a container? The hit the container
In this picture, on how many spheres is the buoyant force less than the weight of the sphere? Four
Why aren’t organisms that live on the seafloor crushed by water pressure? The pressure inside its body is balanced with the pressure outside its body
The relationship between buoyant force and weight of a displaced fluid was first stated by Archimedes.
A ball of clay sinks when placed in water. The same piece of clay floats if it is made into the shape of a boat. Compare the volume of water displaced by the ball with the volume displaced by the boat shape. The boat shape displaces a larger volume of water
How are density and buoyancy related? When an object is less dense than the fluid it is in, the buoyant force will allow the object to float. If the object is more dense the buoyant force will not be great enough and the object will sink.