Tse Science 8 Name: _________________________

Name: _________________________________________

Class: ___________________________________________

Science 8

Fluids Miss Tse

Tse Science 8 Name: _________________________

Unit 3: Topic 1

Flowing Along

Fluid:

Viscosity:

The States of Matter

1. Solid

2. Liquid

3. Gas

Tse Science 8 Name: _________________________

Particle Theory of Matter

1.

2.

3.

4.

5.

Changes of State

Tse Science 8 Name: _________________________

Sublimation:

Ex. When frost forms on windows

Evaporation:

Boiling:

Similar to boiling point, every substance has its own __________________ point and

______________________ point.

Ex. The freezing and melting point of water is ___________.

Tse Science 8 Name: _________________________

Unit 3: Topic 2

How Fast Do Fluids Flow?

Some fluids can flow faster than others!

You can actually measure how fast a fluid flows from one point to another (its distance).

This is called _______________________.

Different factors can affect the flow rate of a fluid such as

temperature and the friction between the fluid and surface

material.

Why do we care about this?

The viscosity of liquids is an important property that must be measured in some industries.

For example, food manufacturers must ensure that the food that

they produce have the right _______________________________.

Ice cream, salad dressings, gravies, pasta sauces, soups, and

syrups all need the proper viscosity.

Another example would be drug companies when they are making their cough syrups.

Cough syrups have ____________________ viscosity yet they are still drinkable so

they can soothe and cool your throat.

Manufacturers also need to know how to regulate the effect of heat on the viscosity of a

substance.

Sugar maple trees produce maple syrup that is very runny and not

sweet to the taste. However, when the sap is heated and the water

evaporates, it turns into the sweet and thick syrup that we love!

Tse Science 8 Name: _________________________

Unit 3: Topic 3

Why Viscosity Varies

Imagine that you and a group of friends are moving through a crowded shopping mall.

Could you make your way through the

crowd more quickly if your group was

smaller or larger?

Small groups can move through a crowd

more quickly than large groups because they

can fit into the empty spaces between other

groups more easily.

The particle theory suggests that small particles can move past each other more easily than large particles

can.

Why is that?

That’s because large particles take up _______________ space.

Now imagine that you, your friends, and everyone in the mall scored some great deals and now everyone

is carrying large shopping bags and backpacks. It would be even more difficult to squeeze through the

crowd because everyone’s stuff would take up even more space.

Some particles are __________________________ than others because of their shape.

For example, oil particles are bulkier than water particles so oil is ________________ viscous

than water.

Tse Science 8 Name: _________________________

Finally, imagine that it is Boxing Day and everyone in the mall is moving very, very slowly and will not

move out of the way as you and your friends try to pass. This means it would take even longer to get

through the crowd.

This is similar to what happens to particles when they are cooled – they slow down.

Even though all fluids flow smoothly, they flow at ___________________________ rates because they

all have different viscosities.

Another way to define viscosity is _________________________________________. This

means that the particles can move around but it may be difficult for them to move around each other.

This resistance creates ____________________________________________.

Some fluid particles find it easier to slip past each other compared to other fluid

particles.

Water particles slip past each other easily whereas the particles of honey have more

internal friction so they do not flow past each other easily.

If fluid particles are relatively large or bulky, these particles take a longer time to pass each other.

This means the substance has a higher viscosity and a lower flow rate.

Tse Science 8 Name: _________________________

How liquids are affected:

A liquid’s ability to flow also depends on the energy that the particles have to move around. The warmer

the liquid becomes, the more energy the particles have to move out of the way and make room for other

particles to pass. When a substance cools, the particles have less energy to move around so the spaces

between them get smaller and smaller.

A fluid’s viscosity ___________________________ as the fluid is __________________________and

increases as the fluid is cooled.

How gases are affected:

Just like liquids, the bigger and bulkier the gas particles, their viscosity increases.

However!

The effect of temperature on gas particles is different!

Gas particles do not depend on an increase in energy or a rise in temperature to move further

apart since the particles are already so far apart to begin with. Instead, the extra energy increases

the internal friction of gas particles because the particles speed up and collide with each other

more frequently. Cooler temperatures in gases keep internal friction and viscosity low.

Table Summary:

Fluid Size of

Particles Shape of Particles Temperature Viscosity

Liquid (ex. Water) Small Warmer

Liquid (ex. Oxygen) Large Cooler

Gas (ex. Oxygen) Small Cooler

Gas (ex. Butane) Large Warmer

Tse Science 8 Name: _________________________

Unit 3: Topic 4

Density and the Particle Theory

Density:

In every day terms, it can be described as the

“crowdedness” of the particles that make up matter.

According to the particle theory, different substances have different sized particles. The size of the

particles determines how many particles can “fit into” a given space.

This means that each substance has its own unique density based on particle size.

So how is density of a substance related to the substance’s physical state?

Imagine filling a container with liquid water and another container with water vapor. Both are the

same substance so their particles are the _______________________ size. But according to our particle

theory, gas particles have ________________ space between them than liquid particles. This means that

the water vapor in the container would have _____________________ particles than the liquid water. So

we can conclude that the density of the water vapor would be ___________________ less than the

density of the liquid water.

Diagram:

Tse Science 8 Name: _________________________

So why can solids move through liquids or

gases?

When an object moves through a fluid, it

______________ particles apart and moves

between them. Particles in a solid cannot be

pushed apart. The __________________

forces among the particles of a solid are

stronger than the ones in a fluid.

_____________________ cannot support

objects in the same way that solids can because

the particles can _____________ apart easily. The attractive forces between liquid particles are not strong

enough to prevent being pushed apart.

This also happens with _________________. Gases are even _____________ dense than liquids or

solids.

For example, when you move through air, you are mostly moving through empty space. You do

not have to move as many particles out of the way as you do in water. This would explain why

running through air would be faster and easier than trying to run through water.

Tse Science 8 Name: _________________________

Unit 3: Topic 5

Density: How are Mass and Volume Related?

Mass:

Volume:

Capacity:

____________________: a push or pull. Measured in Newton’s

Weight:

MASS AND WEIGHT ARE NOT THE SAME!

Mass does not change based on location whereas weight will

change depending on where you are!

For example, your weight will be less on the Moon because

there is less gravity pushing on you.

Tse Science 8 Name: _________________________

Density:

Here is the formula for density:

The unit for density for solids: ________________________________________

The unit for density for liquids/gases: _________________________________

When you _____________________ the volume of any substance, the mass will also _______________.

Therefore, the mass to volume ratio will remain constant.

According to the particle theory, the ____________ of the particles in a substance does not change when

the mass or volume of the substance changes. A certain number of particles of a particular size will

always occupy a certain space. As the number of particles increases from substance to substance, the

space required for those particles must also increase.

Example #1

What is the density of 500 grams of sugar in a volume of 3.15 litres measured in g/L?

Tse Science 8 Name: _________________________

Example #2

What is the density of 350 grams of sugar in a volume of 5.16 liters measured in g/L?

Example #3

A block of aluminum occupies a volume of 15.0 mL and weights 40.5 g. What is its density?

Example #4

What is the density of 200 grams of sugar in a volume of 0.645 L measured in g/mL?

Tse Science 8 Name: _________________________

Unit 3: Topic 6

Buoyancy: The “Anti-Gravity” Force

Buoyancy:

The particles of a fluid exert a force in a direction opposite to the

force of gravity. The force of gravity pulls down towards the center of the

Earth whereas buoyancy pushes up, away from Earth.

Floating:

So why can people travel in the air and on water if the density of our bodies is greater than the density of

air and water? Why don’t they sink?

Water can ______________________ objects that have densities greater than water as long as the

weight of the object is ___________________ over a large enough area.

Archimedes’ Principle

Back in 212 B.C.E, a Greek scientist named Archimedes was asked by the king to find

out whether or not his crown was made entirely of gold. Archimedes knew that all he had

to do was determine whether the density of the crown matched the density of the

gold.

Density requires two values: _____________ and _______________.

Archimedes could easily measure the mass using a balance but he had to figure out a

way to measure the volume of an object that was so weirdly shaped.

One day as he went to take bath, he figured out how to solve his problem!

When he stepped into the almost full bath, water gushed out of it.

A solid object can displace water out of a container.

(A solid object can move water of the way.)

Tse Science 8 Name: _________________________

Archimedes figured out that the water that was displaced in the tub must have exactly the same volume as

his body.

So he submerged the crown into a container full of water and then collected and measured the volume of

the water that spilled out. After he did his calculations, he showed that the crown was actually made out

of gold and silver, and not pure gold which meant that the gold smith had lied to the king.

Archimedes then applied his new ideas to another property of fluids…

He believed that the displaced fluid held the key to whether the object placed in the fluid would

sink or float.

He came up with:

The amount of buoyant force that would push up against the object immersed in the fluid

would ____________ the force of gravity (the weight) of the fluid that the object displaced.

Neutral buoyancy:

If 1L of water is displaced, the object replacing it would have the same volume (1 L) but it might have a

different weight than the 1 L of water.

If the object is heavier than the displaced water, then the weight of the object will be a force

greater than the buoyant force that had supported the displaced water.

Tse Science 8 Name: _________________________

Diagrams:

Rock sinking Helium balloon rising Floating boat

Archimedes Principle:

The relationship between buoyancy and density is the basis

for the _______________________.

This is an instrument designed to measure liquid

density. It is highly used in food and beverage

industries.

For example, they can be used to determine the

sugar content of canned fruit syrup or the alcohol

content of wine.

Tse Science 8 Name: _________________________

Unit 3: Topic 7

All about Pressure in Fluids

Pressure:

If the force is increased, the pressure is increased.

Formula for Pressure:

Units for pressure: ____________________________

Ex. What pressure will be exerted by a 10 N box that has equal sides of 3 meters?

Ex. The force of an object is 100 Newtons. The area on which the force acts is 2 square meters. What is

the pressure in Newtons per square meter?

Tse Science 8 Name: _________________________

Pressure and the Particle Theory

The particle theory states that particles in solids, liquids, and gases are constantly moving. Particles move

quickly if they have a great deal of energy. They move more _________________ if they have ______

energy. When particles move, there is always a chance that they will bump into each other. When a

collision occurs, the particles move apart, leaving only empty space between them.

So how come fluids, such as juice in a cup, appear to be at rest if their particles are

moving?

Moving particles exert a force in the direction of ____________ motion.

Fluid particles are moving in all directions at all times. Therefore, most of

the forces _______________ each other out, but some are not cancelled.

These forces are exerted against the walls of the container causing

_____________________.

Now what happens if there was a hole or crack in the container?

Regardless of where the hole or crack is, the fluid __________________________.

This means that the pressure of a fluid is exerted equally in ALL directions.

As the particles in the inner walls of the

container apply pressure on the fluid to stay

inside the container, the particles of the fluid

press against the container with an equal

force.

Tse Science 8 Name: _________________________

Compressibility

The particles in a fluid push against each other until something stronger exerts a force in the opposite

direction.

For example, what happens when you squeeze a bottle filled with water? Is it possible for the

particles of the fluid to move closer together when this pressure is applied?

According to the particle theory, the amount of empty space between particles depends on two factors:

1. The physical state of the substance (whether the substance is a solid, liquid, or gas)

2. The amount of energy that the particles have

An interesting property of gases is the ______________________________. This is the ability to be

squeezed into a smaller volume. Gases are compressible because gas particles are extremely far apart.

If it is unable to be squeezed into a smaller volume, it

is _______________________________.

Instead of changing the volume of either the solid or liquid, the

applied force is transmitted (passed along) from one particle to

the next.

Flow Pressure:

This is something you experience almost every day. When you are walking outside and

wind lifts your hair or pushes against you, you are experiencing flow pressure.

Static Pressure:

Do your ears start to hurt when you are swimming too deep underwater? This is static pressure!

Tse Science 8 Name: _________________________

Unit 3: Topic 8

Water Pressure and Hydraulic Systems

Can we compress liquids?

When we try to compress liquids, we are exerting a force. What happens to the liquid?

As long as the liquid is ______________________ and _____________________ in a tube or a pipe, the

force will be transmitted along the liquid until something moves or bulges.

Hydraulic Systems

Hydraulics:

Devices that transmit applied forces through a liquid to move into

something else because of pressure is called _____________________.

Rescue workers use hydraulic-powered devices to cut away or move heavy

metal at the scene of car crashes. One of the devices is called the Jaws of Life.

It’s a powerful pump that is used to move hydraulic fluid continuously through

the hoses to produce a strong force in the rescue tool.

Another example would be the dentist chair that you sit in! It

can be lowered, raised, or tilted because of a hydraulic

system.

Hydraulic systems can be used to transport _________________ over large

distances.

In Ancient Rome, Romans constructed huge aqueducts to transport

water from lakes to distant cities.

Today, water, natural gas, and oil are examples of fluids that are

transported in extensive pipelines.

So think about the water that comes out of your faucet!

Where does the water come from?

Drinking water comes from ____________________________________ deep in Earth’s crust.

Tse Science 8 Name: _________________________

So how does water travel up to people’s homes or hi-rise apartments?

To travel so high, the water must be placed under _________________ in order to give the

particles the energy to move against __________________. The amount of

pressure must be enough to transport the liquid over a distance but not enough

that the pipes burst!

Numerous bends or rough surfaces in the pipes can cause

_________________________, which will affect fluid pressure. The particle theory

suggests that particles lose energy as they brush past each other in confined spaces. Therefore, we need

things like pumping stations to restore the pressure lost on long routes to people’s houses and businesses.

In these transport systems, it is important that the fluid keeps travelling away from the pump!

One way ___________________ are installed to regulate the flow of a liquid in hydraulic

systems.

Body Hydraulics

One of the most efficient hydraulic transport systems that you learned about

already is the human circulatory system. Blood must be kept under pressure

so it can reach all parts of the body.

The ______________________ blood pressure occurs close to the heart

whereas the ________________ occurs at the hands and feet. Blood

pressure increases and decreases between heartbeats. Your blood pressure is

measured using a sphygmomanometer. A normal blood pressure is 120/70.

Tse Science 8 Name: _________________________

Unit 3: Topic 9

Air Pressure and Pneumatic Systems

Pneumatics:

So why do not you feel weighed down by air?

The pressure of Earth’s atmosphere is so well balanced by your body, inside and out,

that you hardly ever notice air pressure.

Just as water pressure changes with depth, air pressure changes with altitude. If you

were on an airplane, your ears would “pop” as your eardrums adjusted to the change in

air pressure.

According to the particle theory, as you climb higher into the atmosphere, fewer air particles press against

you on the outside of your body. The air pressure INSIDE your body does not change as quickly

however. That is why your eardrum moves in response to the difference in pressure.

On average, the atmosphere exerts a force of 10 N or 101 300 Pa on every cm² on Earth’s surface at sea

level.

Barometer:

The earliest barometers were made with mercury and some of them are

still being used by weather stations.

First, a thin strong-walled glass tube is sealed at one end and open at the

other. This tube is completely filled with mercury. It is then inverted so no

air can enter. The mercury falls to a lower level due to gravity leaving a

vacuum.

So how come some mercury stays in and some comes out?

As the air pushes down on the mercury in the pool, forcing it up the column, the mercury pushes

down through the column and into the pool because of its weight. The mercury will stop moving

when the force of the air pressure pushing it up equals the force of gravity pulling it out.

Tse Science 8 Name: _________________________

A more convenient and safer option is the _______________________________,

which contains no liquid at all.

Pneumatic Systems

Pneumatic systems are similar to hydraulic systems except ________________ are

used instead of liquids.

Pneumatic Systems:

The reason why pneumatic systems works is because gases can be compressed. Therefore,

____________________ are needed for pneumatic devices to operate.

Compressors:

As air pressure builds up in these devices, all the built up air pressure needs to be released

somehow. Therefore, ________________________ are also needed for pneumatic devices to

operate.

Decompressors:

Ex.

Tse Science 8 Name: _________________________