# 12.1-12.3 Notes

## 90 terms

### weight,water

The ___________ of ____________ makes things float.

### to take the place of an object

What does the word "displacement" mean?

### the shape makes the difference

A ball of tin foil sinks to the bottom of an aquarium. Another piece of tin foil the same size can float. What maes the difference?

### he figured out displacement and volume by getting into a tub and the water flowed over the tub.

What did Archimedes figure out about displacement and volume?

### things float

If an object has positive buoyancy, what will it do when placed in water?

### things sink

If an object has negative buoyancy, what will it do when placed in water?

### hover when denisty equals the fluid buuoyant force

If an object has neutral buoyancy, what will it do when placed in water.

### when you are in a submarine, swimming, scuba diving, or when you just need it

When is neutral buoyancy useful or necessary?

### the force per unit area thats applied on the surface of an object, force divide by area, Pascall N/M^2

What is pressure? How is it calculated? What is the unit label for pressure?

### because the pressure exerted by the higher column of water is greater

Two containers have the same amount of liquid in them. Why does one have greater pressure than the other?

### the angle of pressure of any object is right to the surface

Describe the angle of pressure on any object that is submerged in a liquid.

### your body is filled with fluids such as blood that exerts pressure, the pressure exerted outward by the fluids inside your body balances that pressure exerted by the atmosphere

Why doesn't the pressure exeerted by our atmosphere crush us?

### the higher the pressure the less atmospheric pressure and air, the deeper the more pressure the higher the less pressure

Describe the changes in pressure that occer as you go from the surface of the earth to the top of a mountain, and from the surface to deep under the water.

### buoyant force is related to newton's 2nd law because the force on it are balanced

How is buoyant force related to Newton's 2nd law?

### buoyant forces caused by the pressure exerted by a fluid on an object that is in the fuid.

Explain how the pressure in a fluid causes a buoyant force.

### unbalanced presure

In terms of buoyant forces, why do some objects float and others sink?

### buoyant force of an object equal weight of fluid displaced by the object

State Archimedes' principle. What does that mean?

### the water is displaced on the steel so it floats, less dense equal float, more dense equals sink

In terms of density, how can you determine whether an object will sink or float?

Why can a boat made of metal that is more dense that water float in water?

### the open container with fluid is different because all of the force is exerted toward the top of the container. The closed container is different because all the forceis exerted on the whole bottle

How is putting pressure on a fluid in an open container different from applying pressure to a fluid in a closed container?

### when a force is applied to a fluid in a closed container, the pressure in the fluid increases everywhere by the same amount

State Pascal's principle of fluids and pressure.

### when the speed of a fluid increases, thepressue exerted by the fluid decreases

State beroulli's principle of moving fluids and pressure.

### the air pressure was pushing on one part of the house so the air went faster as the air in the house decreased

Use Bernoulli's priniple to explain how the difference in air pressure during a big storm can damage a house.

### he figured out displacement and volume by getting into a tub and the tube over flowed

State Archimedes' principle as it relates to floating and buoyancy.

### French scientist Blaise Pascal

Who named the Pascal?

### true

Does fluids take the shape of their container?

### The narrow tube has greater pressure at the bottom. Whenever the height of the fluid is highest, the pressure is greatest at the bottom

Two containers have the same amount of liquid in them. Which one has greater pressure at the bottom? Why?

### type of liquid or gas is used, and the depth of the fluid you are measuring

What does fluid pressure depends on?

### always at right angles to the surface of the object

Where is fluid pressure on a object?

### on the depth of the object in the fluid

What does pressure depends?

### it does not affect fluid pressure

Does the shape of a container and the area of the bottom of a container affect fluid pressure?

### they all have the same pressure and that the pressure of all the particles at any given level is the same

Why does it mean that all liquids rise to the same level?

### the forces on it are balanced, the pull of gravity is equal to the supporting force of the fluid.

What does it means when something is Buoyant Forces?

### upward, down

Buoyant force is the ______ force of the fluid working against gravity pulling _______

### less dense, float

(Denisty & Buoyancy) If the object is _________ than the fluid it will _______. Its buoyant forces are greater than its weight

### more dense, sink

(Denisty & Buoyancy) If the object is _________ than the fluid it will _______. Its buoyant forces are less than its weight.

### Its buoyant force is greater than its weight. It is less dense than the water.

Why does an iceberg floats?

### its shape displaces a large volume of liquid, making a large buoyant force that counteracts its huge weight

Why does a boat float?

### weight of fluid displaced

What does buoyant fluid depends on?

### weight of fluid displaced, partially submerged, displaces less fliud, buoyant force will be less

The buoyant force depends on the _______________. When the object is _______________ it ______________ than when it is fully submerged. That means that its ________________ when it is partially submerged.

### pressure

__________ is the force per unit area applied on the surface of an object.

### pascal

The SI unit of pressure is the __________.

### the force and the area over which it is applied

What two things must you know to calculate the pressure exerted on a surface?

### pressure = force/area

Pressure is defined as __________.

### 817 Pa

If a 5-kg box contacts your hands over an area of 625 cm2, how much pressure is exerted on your hands by the box?

### The pressure exerted on object B is twice as great as the pressure exerted object A

The same force is applied to two different objects. The area over which the force is applied to object A is twice as large as the area over which the force is applied to object B. Which of the following statements is true of these objects?

### fluid

A __________ is any substance that has no definite shape and can flow.

### increases, increases

As the height of a fluid above a surface __________, the pressure exerted by the fluid on that surface __________.

### perpendicular to all surfaces of the object

In which direction is pressure by a fluid exerted on an object that is submerged in it?

### 100,000 Pa

What is the approximate pressure exerted on your body by the atmosphere at sea level?

### barometer

An instrument called a(n) __________ is used to measure atmospheric pressure.

### on the bottom

If a cube is submerged in water, where on the cube is the pressure exerted by the water the greatest?

### buoyant force

The supporting force exerted by a fluid on an object immersed in it is called __________.

### 50 kg

An object weighing 50 kg is floating in a fluid. What is the buoyant force of the fluid on the object?

### whether the buoyant force is larger than the object's weight

What determines whether an object will sink or float?

### The buoyant force on a submerged object is the same at any depth.

At what depth is the buoyant force on a submerged object the greatest?

### the buoyant force on an object is equal to the weight of the fluid it displaces

Archimedes' principle states that __________.

### density

The __________ of an object is the mass of an object divided by the volume it occupies.

### is transmitted unchanged throughout the fluid

According to Pascal, pressure applied to a fluid __________.

### increases, decreases

Bernoulli's principle states that as the velocity of a fluid __________, the pressure exerted by the fluid __________

### hydraulic system

A(n) __________ uses a fluid to increase an applied force.

### 75 cm2

A force of 150 N is applied to a 25 cm 2 piston in a hydraulic machine. What is the area of a larger piston if the force available in it is 450 N?

### 40 N

The area of the small piston in a hydraulic system is 1 m2. The area of the larger piston is 4 m2. If a force of 10 N is applied to the small piston, what is the force available in the large piston?

### Air pressure is greater below the wings, creating lift

How does Bernoulli's principle explain how airplanes fly?

### 85 Pa

A force of 17 N is exerted on an area of 0.20 m2. What is the pressure?

### The floating ball has a lower density

A child throws two balls into water. One ball floats and one sinks. Which of these is correct?

### The pressure exerted by the fluid decreases

According to Bernoulli's principle, which of the following happens when the speed of a fluid increases?

### 53 N

The pressure inside the fluid of a hydraulic system is increased by 875 Pa. What is the increase in the force exerted on a piston that has an area of 0.060 m2?

### a 55-kg boy standing on one foot

Which of the following exerts the greatest pressure on the ground?

### 98 g

What is the mass of a 11-cm3 strip of copper if its density is 8.9 g/cm3?

### a hydraulic system lifting heavy weights

Which of the following is explained by Pascal's principle?
A)airplane wings lifting into the air
B) a heavy ship floating in water
C) hot air rising in a fireplace
D) a hydraulic system lifting heavy weights

### ice

Which of the following is NOT a fluid?

A) steam
B) water
C) ice
D) pure oxygen

### the sandbag has weight and when it is dropped the hot air balloon has less mass holding on to it

A sandbag is dropped from a hot air balloon and the balloon rises. Explain why this happens

### the watr adds weight to the boat and when the boat's weight becomes greater than the buoyant force it sinks

Explain why a leaking boat sinks.

### all of the weight is distributed with the water so the density equals the fluid buoyant force

Explain why it is easier to lift an object that is underwater than it is to lift the object when it is of the water.

### one of them could have the same shape, but more mass or had something heavy in it so it sun and other one could have floated because it was untouched

Two objects with identical shapes re placed in water. One object floats and the other object sinks. What diference can you infer between the two objects that causes one to sink and other to float.

### pascal's principle

What principle is this? When a force is applied to a fluid in a closed container, the pressure in the fluid increases everywhere by the same amount

### archimedes' priniciple

What principle is this? The buoyant force on an object is equal to the weight of the fluid it displaces.

### bernoulli's principle

What principle is this? When the speed of a fluid increases, the pressure exerted by the fluid decreases.

### low pressure at the top of the tube, high pressure in the liqued in the bottle pushes up the tube into the stream of air, making it spray

How does Bernoulli's principle deal with a spray bottle?

### the air moving past the chimney lowers the air pressure above the chimney. As a result, smoke is forced up the chimney faster than when air above the chimney is still

How does Bernoulli's principle deal with smoke going up a chimney?

### low pressure pushing down, high pressure pushing up to make the plane lift up

How does Bernoulli's principle deal with airplanes flying?

### the weight is sreadout on the water, the ball has les water pressure aound it so it sinks

How does Archimedes principle deal with an aluminum boat that can float but ball of aluminum sinks.

### as pressure us added to a fluid, the fluid distributes the increased pressure equally through the whole container

Cartesian diver (pipette in bottle) [Pascal's principle]

### the air pressure becomes less as you go higher due to gravity.Our bodies are adjusting to the change of the air pressure so your ears start to pop

Why do your ears "pop" on a mountain at high altitudes?

### sinks

What happens when buoyant force is greater than the weight of an object in it?

### floats

What happens when buoyant force is less than the weight of an object in it?

### hovers

What happens when buoyant force is equal to the weight of an object in it?

### 25n/m^2

What is the pressure that results when a force of 100-N is placed on an area 4 m^2.

### 240n/m^2

A bottle of lemonade sitting on a table weights 6-N. The bottom of the bottle has a surface area of 0.025 m^2. Calculate the pressure the bottle of lemonade exerts on the table.