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Save a master copy of the review to your hard drive. Then open a second copy and label it “Review and the date” for example “ReviewMarch20) then you can go through and delete things you already know and change the colors. If you make a mistake go back to the saved original and start again.

S8P1 – STRUCTURE OF MATTER

- Distinguish between atoms and molecules

- Recognize Pure Substances as Elements or Compounds.

- Explain the difference between Pure Substances and mixtures

o ELEMENTS ARE MADE OF ATOMS. COMPOUNDS ARE MADE OF MOLECULES. BOTH ARE PURE SUBSTANCES MADE BY CHEMCIAL BONDS.

o Elements are made of atoms. A element is a substance that is full of only one type of atoms. The element oxygen is all oxygen atoms..

▪ ATOM DIAGRAM – Protons are positive, Neutrons are neutral. They make up the nucleus and the atomic mass. Electrons are negative and very very small. So that positive charges = negative charges, the number or protons is equal to the number of electrons.

[pic]

o Compounds are made of molecules. Molecules are two or more different type atoms combined chemically. See the picture below

o

▪ COMPOUND DIAGRAM- This is hydronium not Hydrogen. Notice the three hydrogen atoms are sharing electrons with one oxygen atom. There are 3 atoms in water (h20) – 2 hydrogen + 1 oxygen. There are four atoms in H202 (hydrogen peroxide) – 2 hydrogen and 2 oxygen.

▪

▪ Elements and compbounds are bonded chemically by sharing electrons.

[pic]

o Compounds have properties that are different from or opposite the properties of the atoms that make them. Hydrogen and Oxygen are gases that burn (combustible) but water is a liquid that does not burn.

Great review videos (3 min each) with quiz for physical science.

o Mixtures are simply things physically combined but not chemically combined. Like putting a bunch of items in a salad. They are not chemically combined and can be easily separated.

o

o solute (sugar) + solvent (water) = solution

When the 2 substances totally mix it is called a solution.

Solute + Solvent = Solution

(sugar) + (water) = Solution

 

[pic]

|HOMOGENEOUS MIXTURES |HETEROGENEOUS MIXTURES |

| The prefixes "homo"- indicate sameness |The prefixes: "hetero"- indicate difference. |

|A homogeneous mixture has the same uniform appearance and composition |A heterogeneous mixture consists of visibly different substances or |

|throughout. Many homogeneous mixtures are commonly referred to as |phases. The three phases or states of matter are gas, liquid, and |

|solutions. |solid. |

| |Graphic on the left of "Dancing Raisins" shows liquid, solid, and |

| |gas substances in a heterogeneous mixture |

Examples

Homogenous – sugar water, salt water, kool aid.

Heterogeneous – water and sand, blood, salad, raisen brand cereal

o Mixtures and Solutions – Physically combined.

- Describe the movement of particles in different states of matter, such as - Sold, liquid, gas, plasma

[pic]

o [pic]

| |Definite Shape |Definite Volume |

|Solid - Ice |Yes – I can’t change the shape without applying|Yes – The pencil has a definite |

| |a force |volume. If I break it in two pieces |

| | |the volume is still the same. |

|Liquid |No – It take the shape of the container I put |Yes – I could not squeeze the syringe |

| |it in. |full of water and make the volume |

| | |smaller. |

|Gas |No – It feels up the container. When Little |No – I can squeeze a balloon and make |

| |Johnny passed gas in class, everyone knew it. |it smaller. |

| |It filled up the container. When he spilt his | |

| |milk hardly anyone knew it because it spread | |

| |out on the floor. | |

|Plasma – no electrons. |No |No |

o

o Solid – particles in solid cannot move but they are always vibrating. They have a definite volume and a definite shape. Since the particles are touching, they have the greatest gravitational attraction with other particles. And they have the least energy.

o Liquid – particles in a liquid can move around each other. They have a definite volume because I can’t squeeze a container of water and make it smaller. But a liquid does not have a definite shape because a liquid takes the shape of the container that I Put it in.

o Gas – Particles in a gas move around each other and take the shape of the entire container they are in (Think of your mom’s cookies). They do not have a definite shape or a definite volume. I can squeeze a balloon. Gas particles have the least gravitational attraction since they are spread out and they have the most energy.

o Plasma – Plasma is the most common state of matter in the universe. It is found in stars where atoms have so much energy that the electrons escape. It is gas atoms with no electrons.

o Phase Changes – These are physical changes. phases of matter can change from one to another. Remember the definitions of the following phase changes:

▪ Melting - melting occurs when a substance changes from a solid to a liquid

▪ Boiling - boiling is when a substance changes from a liquid to a gas both on the surface and inside a liquid. FAST.

▪ Evaporation – is when a substance changes from a liquid to a gas only on the surface of a liquid. SLOW

▪ Condensing - condensation is when a gas changes to a liquid

▪ Freezing - freezing is when a liquid changes to a solid

▪ Sublimation – going straight from a solid to a gas with no liquid state. Dry Ice is an example.

▪ Deposition – going straight from a gas to a solid with no liquid state.

[pic]

| |

|  |

- Recognize physical properties of matter, such as: density, boiling point, melting point, dissolving.

o Physical Properties - Physical properties are those that can be observed without changing the identity of the substance. The general properties of matter such as color, density, hardness, are examples of physical properties.

o Phase change is a physical property.

o

o Density is a physical change.Remember 1 ml = 1 cm3 (centimeter cubed). So a volume of 25 cm3 is the same as 25 ml.

o Melting and Boiling Point – For a pure substance like water, the melting point is the same temperature as the freezing point.

o If the pure substance is taking in energy (endothermic) the object is melting. If energy is exiting the pure substance (exothermic) the object is freezing.

o [pic]

o Dissolving – Dissolving is a physical property because there is no new substance. The properties of the salt do not change and the properties of the water do not change. Just the appearance changes. Salt and water are easily separated by boiling the water. The salt is left in the pan.

Density diagrams [pic]

[pic]

- Recognize the chemical properties of matter, such as: reactivity, combustibility, tarnish, rusting, oxidation.

o Chemical Properties – properties that change the chemical nature of matter. It produces a new substance (e.g., burning, rusting, photosynthesis). Molecules and Atoms combine and separate chemically to form new molecules.

o The original substances cannot be separated from one another if a chemical change took place.

o Reactivity – The ease and speed with which atoms and molecules act with other atoms and molecules to form new substances.

▪ The first column or family of metals are the most reactive.

o Combustability – The ability of a substance to react with oxygen and burn.

o Tarnish – A new substance formed on silver and metal that makes it look dull instead of shinny.

- Distinguish between changes in matter as physical or chemical changes.

o The changes that take place in substances may be categorized in two classes:

▪ Physical Change - does not produce a new substance (e.g., phase changes, crushing a can)

▪ Chemical Change - produces a new substance (e.g., burning, rusting, photosynthesis)

▪ Color is a physical property. A change in color shows a chemical change has happened.

- Distinguish between properties of matter as physical or chemical properties:

o The properties of matter can be characterized as physical or chemical propertries.

▪ Physical Property - A physical property is an aspect of matter that can be observed or measured without changing it. Examples include color, molecular weight, density, texture.

▪ Chemical Property - A chemical property may only be observed by changing the chemical identity of a substance. This property measures the potential for undergoing a chemical change. Examples of chemical properties include reactivity, flammability and oxidation states.

- Recognize that more than 100 elements can be organized on the periodic table based on similar characteristics. Metalloid Dance

o Atomic number. Atoms are organized according to the number of protons. Starting at the top with hydrogen that has one proton. The number of protons is the atomic number. So they go across 1, 2, 3, … And then across again

o Families or Groups go up and down (horizontally) and all the elements in a family have the same or similar properties.

o The first family or group are the most reactive and become less reactive as I move toward nobel and inert gasses.

o Nobel or Inert Gases. Family or Group 18 the last one are the noble or inert gases are not reactive. They do not react with other elements.

- Explain that some elements have similar properties as shown on the Periodic Table of Elements such as metals, non-metals.

-

o Metals – shinny, good conductor of heat/electricity, solid, reactive, hard texture, combustible, malleable (hammer into shape), ductile (pull into a wire).

o Nonmetals - There are three types of nonmetals – metalloids, nonmetals, nobel/inert gases.

▪ Metalloids – fuses and semiconductors.

▪ Non-metals. The opposite of metals. Dull, poor conductors of heat/electricity, not reactive, soft, not malleable or ductile.

▪ Nobel/Inert Gases – not reactive.

▪ Atomic number. Atoms are organized according to the number of protons. Starting at the top with hydrogen that has one proton. The number of protons is the atomic number. So they go across 1, 2, and then go across 3,4,…9, 10, and then go across11, 12, …17, 18 ..

▪ Take a look at the diagram below. Notice that nobel/inert gases are part of the non/metals. And metalloids are called semi-metals.

▪ You should know the metalloid dance well enough to identify the parts of the diagram below. What are 100, 18, and 7.

|[pic] |

- Demonstrate understanding of the Law of Conservation of Matter

o Matter can be neither created nor destroyed. Just transformed into something else. So if I burn a log, even though the log seems go disappear, the number of total atoms remains the same. Many of them are now floating in the air.

o This is addition. 50 g. of Hydrogen + 25 g. of Oxygen create a product of 75g of H20 (water).

o Here two liquids are combined to make a solid. Notice the total mass remains the same. Before the matter is 92.95 g (grams) and after the matter is 92.95 g.

o [pic]

Photosynthesis - The ultimate chemical change and transformation of energy . EM radiation (photons) is transformed into stored chemical energy plants.

[pic]

S8P3 and S8P5 FORCE AND MOTION

- Determine the relationship between velocity and acceleration

o [pic]

o Velocity is speed in a particular direction.

o Acceleration is going faster, going slower, changing direction.

o Remember acceleration is measured in m/s2 (meters per second squared) and speed is measured in m/s (meters per second).

[pic]

o Even throwing a ball, we are talking about vectors (straight lines in a particular direction). Vectors are the direction a speed is moving. The formula for acceleration is (final speed – initial speed) divided by time.

o [pic]

- Demonstrate understanding of the effect of balanced and unbalanced forces

o Newton's first law of motion An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

o

o Now consider a book sliding from left to right across a tabletop. Sometime in the prior history of the book, the book was given an applied force and set in motion from a rest position. Our focus is not upon the history of the book but rather upon the current situation of a book sliding to the right across a tabletop. The book is in motion and at the moment there is no one pushing it to the right. (Remember: a force is not needed to keep a moving object moving to the right.) The forces acting upon the book are shown below.

o

- [pic]

o Notice in the two diagrams below, when the friction force is balanced or equals the applied force, there is not motion since the forces are balanced. When the applied force is greater than the friction force, then there is an unbalanced force and that force overcomes inertia.

Moving -( Not Moving

- [pic][pic]

- Explain the relationship between the amount of force needed to move an object and its mass (inertia)

o It is easier to push a child then and elephant, and it is easier to stop a running child then a running elephant because the more mass (inertia) and object has, the more unbalanced force I must apply to the object to get the object to change what it is doing.

▪ So the more mass an object has, the more force I need to move it.

▪ momentum is mass times velocity of an object. Inertia is the amount of force needed to move an object. The higher its mass the higher its inertia.

▪

o [pic]

- Explain the effect of forces (gravity and friction) on the motion of an object

o The force of gravity

-  

▪ [pic]

▪ Gravity is a force that pulls on you down to the center of Earth.  Or it would if the ground didn’t stop you. 

-  

▪ Unless there is strong air resistance (a piece of paper), two objects released at the same time and height, hit the ground at the same time.

[pic]

-

▪ Notice that nothing was said about mass.  Whether you are a teacher like me, who is as anorexically thin as a model, or fat a a cow – both will fall at the same rate.

o Another common everyday force is friction. 

-

▪ Friction depends on how hard two surfaces press on each other and the type of surfaces (ice, rubber basketball shoes, etc).

▪ Friction always goes in the direction opposite to where you are moving.

▪ FRICTION IS A FORCE IT IS NOT A FORM OF ENERGY!!!!.

▪

▪ Friction is a force that resists motion and only occurs when things slide or roll against each other, when things are not moving (static friction), or when things move through a fluid (fluid friction like air resistance).

-

- Demonstrate understanding of the effect on work by simple machines, such as:

○ levers ○ inclined planes ○ pulleys ○ wedges ○ screws ○ wheels and axles

o If distance goes up (a ramp) then force goes down. If I jump up the stairs, distance goes down so force must go up.

o

o But total work is always the same. Here 5 times farther = 1/5 the force.

[pic]

o Work, Power and Force are measured in?

▪ I work to make money to buy Jenny some Joules.

▪ Power is measure in watt? Exactly.

▪ I use force to open my Fig Neutons.

▪ AND ACCELERATION IS MEASURED IN METERS PER SECOND SQUARED. m/s2

o To do work, I must move an object some distance. If the object does not move then I did not do any work.

o Power is how fast I did the work. A hurricane and a soft breeze do the same amount of work moving a leaf but the hurricane does it faster so the hurricane has more power. Power = work divided by time.

o If you are a left brain thinker you will enjoy this diagram. If you are right brained, you enjoy organized notes more.

o [pic]

o Energy and work are both measured in joules. This makes sense. I need energy to do work.

-

[pic]

Yes – for every action there is an equal but opposite reaction. When he pulls, an unbalanced force is applied from wheels to ground and ground to wheels. So they don’t cancel. No – tree did not move. No. Must move to do work.

|Table of Simple Machines |

|  |

|Simple Machine |

|Description |

|What it does |

|Examples |

| |

| The Lever Family |

| |

|Lever |

|A stiff structure that pivots on a support called a fulcrum |

|Lifts or moves loads |

|Shovel Nutcracker Seesaw |

|Crowbar |

|Elbow |

|Tweezers |

|Bottle opener |

| |

|Pulley |

|A grooved wheel with a rope or cable around it |

|Moves things up, down, or across |

|Flag pole |

|Crane |

|Curtain rod |

|Tow truck |

|Mini-blind |

|Bicycle chain |

| |

|Wheel and axle |

|A wheel that turns about an axle through its center; both wheel and axle move together |

|Lifts or moves loads |

|Ferris wheel |

|Bicycle pedal |

|Bicycle wheel |

|Car wheel |

|Wagon wheel |

|Doorknob |

|Pencil sharpener |

|Wind-up hose |

| |

|Inclined Plane Family |

| |

|Inclined plane |

|A sloping surface connecting a lower level to a higher level |

|Things move up or down it |

|Wheelchair ramp |

|Slide |

|Stairs |

|Escalator |

|Slope |

| |

|Wedge |

|An object with at least one slanting side ending in a sharp edge |

|Cuts or spreads an object apart |

|Knife |

|Pin |

|Nail |

|Chisel |

|Ax |

|Hatchet |

|Fork |

|Snowplow |

|Front of a boat |

| |

|Screw |

|An inclined plane wrapped around a cylinder |

|Holds things together or lifts |

|Screw |

|Jar lid |

|Vise |

|Bolt |

|Drill |

|Corkscrew |

| |

|  |

o There are two kinds of mechanical machines, simple and compound. 

-  

o A simple machine is a single mechanical device.

-  

o A compound machine uses more than one simple machine in it. 

-  

o Mechanical advantage –

o

o The work a machine does is called work output.  The energy or work put in the machine is called work input.

o Efficiency = work output/work input

o An ideal machine would be 100% efficient. There is no such thing.

- Explain that every object exerts gravitational force on every other object

-

o If I go to the moon with my science book, the weight of the book changes but the mass of my book stays the same.

o Explain that the gravitational force exerted on objects depends on how much mass the objects have and how far apart they are

▪ Every object exerts gravitational force on every other object. The force depends on how much mass the objects have and on how far apart they are. The force is hard to detect unless at least one of the objects has a lot of mass.

o Newton's Law of Universal Gravitation

Mass = a quantity of matter.

The more mass an object has, the harder it is to move.

More force is needed to give the same acceleration to a more massive object. Twice the mass requires twice the force.

|All masses are attracted to other masses (gravity) |

|Gravity is changed by mass. | |

| |[pic] |

| |More Mass/Gravity Less Mass/Gravity |

|If the mass of one or both of the objects is increased, then the gravity | |

|between them is also increased. | |

|Gravity is changed by distance |[pic] |

|If the distance between the objects is increased, then the gravity between them| |

|is decreased. | |

|The amount of gravity between two objects is called weight. |

- Describe the advantages and disadvantages of series and parallel circuits

- Distinguish between how series and parallel circuits transfer energy

- Distinguish between how series and parallel circuits transfer energy

o Series and Parallel Circuits are under force and motion because electricity moves.

| |Series |Parallel (how many lines for parallel lines|

| | |– at least.. |

|One bulb goes out |All the lights go out |The other light stay on |

|Add bulbs |Since they are all sharing the electricity,|the bulbs stay the same brightness. |

| |the bulbs get dimmer | |

|What happens to resistance |Every time I add a light, there is more |Since there are more than one way for the |

| |resistance (friction) so the bulbs get |electricity to go, friction or resistance |

| |dimmer. |does not increase. |

o

o Series Circuits

▪ [pic]

\

o Parallel Circuits – How many lines do I need for a parallel line? How many ways to get back to the batter do I need for a parallel circuit?

-

[pic]

▪

o The bulbs in a series circuit are dim for two reasons:

▪ The current going through them is smaller because two bulbs in series have a higher resistance than a single bulb.

▪ Each charge only gives up some of its energy in each bulb

-

o Voltage and current –

▪ Voltage is how much electricity is entering the electric system. Current is how much electricity is going into the appliance on the system. Think of a water faucet as the volatage, and the water coming out of the hose as the current. And the friction of the garden hose on the water is resistance.

- Explain that electric currents and magnets can exert force on each other

-

o This basic relationship between electric current and magnetic fields results in some interesting interactions:

▪ Many electromagnets work by the following principle: A coil of wire is made so that when voltage is applied the current will follow a circular path.

o [pic]

o Magnets and Electricity When the battery is disconnected, the compass would point north. Notice the compass changes when the positive and negative are reversed on the battery.

[pic]

▪ Magnets are different. In magnets, most of the electrons at one end are spinning in one direction. Most of the electrons at the other end are spinning in the opposite direction. And they are all lined up in what is called a domain.

- [pic]

Bar Magnet

▪ This creates an imbalance in the forces between the ends of a magnet. This creates a magnetic field around a magnet. A magnet is labeled with North (N) and South (S) poles. The magnetic force in a magnet flows from the North pole to the South pole.

- [pic]

▪ Have you ever held two magnets close to each other? They don’t act like most objects. If you try to push the South poles together, they repel each other. Two North poles also repel each other.

▪ Turn one magnet around and the North (N) and the South (S) poles are attracted to each other. The magnets come together with a strong force. Just like protons and electrons, opposites attract.

- [pic]

▪ Like sides attract. Opposite sides repel.

▪

S8P2 S8P4 – Energy and its Transformation.

- Explain energy transformation in terms of the Law of Conservation of Energy

|according to law of conservation of energy - energy can neither be created nor be destroyed but can be converted from one form to |

|another. |

| |

|Because it tells you that energy is not used up. You still have it, but it is converted into different forms. |

- Describe the relationship between potential and kinetic energy

o Mechanical Energy is the total kinetic energy + total potential energy

o Potential energy is stored energy. Kinetic energy is energy of motion.

Where is maximum potential energy and where is maximum kinetic energy?

|[pic] |[pic] |

[pic]

o According to the law of conservation of energy, energy cannot be created or destroyed; hence this energy cannot disappear. Instead, it is stored as potential energy. Think of a roller coaster or the man on this bicycle.. When a roller coaster climbs a hill or the man on the bicycle climbs this hill, it has potential energy. At the very top of the hill is its maximum potential energy. When the roller coaster or the man on the bicycle speeds down the hill potential energy turns into kinetic. Kinetic energy is greatest at the bottom.

• Compare and contrast different forms of energy, such as:

○ heat ○ light ○ electricity ○ mechanical motion ○ sound

Study the Pictures

[pic]

[pic]

o Energy occurs in many forms including: chemical energy, thermal energy, electromagnetic radiation, gravitational energy, electric energy, elastic energy, nuclear energy, rest energy. These can be categorized in two main classes: potential energy and kinetic energy.

-

- Describe the transfer of heat by different processes, such as:

-

o Temperature and Thermal Energy –

o

▪ Thermal energy is the total kinetic and potential energy of all the atoms or particles in a substance and temperature is the average measure of that energy.

▪

The basic unit of temperature in the International System of Units (SI) is the kelvin. It has the symbol K. In the United States, the Fahrenheit scale is widely used.

o Energy always moves from hot to cold. – What are the hands motion for conduction, convection and radiation?

o the collision of atoms in matter by conduction- this is touching

o the flow of currents in a fluid (a gas like the air we breath, or a liquid like water) by convection

o

▪ Convection is the movement of molecules within fluids (i.e. liquids, gases). It cannot take place in solids.

▪

o the movement through space by radiation – EM waves and photons.

▪ Radiation In this case from the electrons of atoms with high energy to the electrons of energy with low energy. The “hot” atoms move slower and the “cold” atoms now move faster until they all move the same speed..

▪ So black objects get hotter because all visible electromagnetic waves and their energy are absorbed by the atoms in the black material.

o Convection says in one fluid like water. Radiation goes from one substance to another without them touching.

[pic]

- Recognize the characteristics of electromagnetic and mechanical (sound) waves

o There are two types of waves. Mechanical and Electromagnetic.

o

▪ Mechanical Waves - A mechanical or material wave is a disturbance that moves through a medium.

•

o Electromagnetic waves - Electromagnetic radiation (often abbreviated E-M radiation

o

▪ All EM waves are transverse waves.

▪

▪ All EM waves travel the fastest and at the same speed in outer space. In empty outer space they travel at the speed of light.

▪

▪ All waves have vibrations. The electrons vibrate in EM waves and send out packets of energy called photons.

▪

▪ Make an “L” with your left hand. L and cut on the radio. Long waves start hear. Make the sign for short with a finger and thumb of your right hand. Now grabba gamma.

[pic]

o There are two ways that waves vibrate. T T Transverse and Loooongitudinal Waves

▪ T T T ransverse waves. All EM waves are transverse waves. A transverse wave is a moving wave that consists of vibrations going up and down while the energy goes agross. The vibrations are occurring perpendicular (or right angled) to the direction of energy transfer.

▪

• There are three types of mechanical waves: Transverse waves, longitudinal waves, and surface waves. Transverse waves cause the medium to vibrate at a 90-degree angle to the direction of the wave. Transverse waves have two parts—the crest and the trough. The crest is the highest point of the wave and the trough is the lowest. The wavelength is the distance from crest to crest or from trough to trough.

o

▪ Looongitudinal waves - Longitudinal waves are waves that have the same direction of vibration as their direction of travel, which means that the movement of the medium is in the same direction as or the opposite direction to the motion of the wave.

▪

▪ also referred to as compressional waves or compression waves.

▪

▪ Standing Wave - It looks like it is standing still. Two opposing waves combine to form a standing wave. This phenomenon can occur as a result of interference between two waves traveling in opposite directions.

o

▪ Standing wave – 2 waves, node, antinode, wavelength. Below is a noise cancelling headphone. Notice you hear nothing since the amplitude is zero.

▪ [pic]

-

-

-

- Describe how the behavior of light waves is manipulated in different processes,

- such as:

o reflection - when sound waves are reflected it is called an echo. Reflection is when light or sound waves bounce off a surface. When a wave strikes a reflective surface, it changes direction, such that the angle made by the incident wave and line normal to the surface equals the angle made by the reflected wave and the same normal line. This is the law of reflection says that the reflected light or sound wave leaves a surface at the same angle it hits the surface.

o

▪ When we see white all the colors are being reflected and when we see black none of the colors are being reflected.

o [pic]

o

▪ When we see black, it is because all the colors are being absorbed and no colors are being reflected.

▪

[pic]

▪ When we see red, all the colors are being absorbed except red which is being reflected.

[pic]

o Diffuse reflection – When reflected light goes in all direction because it hits a rough surface. Think of light hitting crinkled tin foil.

o

o The Law of Angle of Reflection – The angle that light or sound waves hit a smooth surface is the same angle that the light or sound is reflected or refracted.

o

[pic]

o refraction – Refraction is the change in direction of a wave due to a change in its speed. This is caused by light entering a new medium. Refraction – change medium. Diffraction, same medium.

|[pic] |[pic] |

o refraction of light going through a different medium. Notice in the first diagram that when light leaves, it is at the same angle as when it entered the solid.

|[pic] |[pic] |

[pic]

o diffraction - when waves go around a barrier – like when you are standing in a dark room and see light coming under a door, or when you are in a classroom and you hear voices in the hall. Think of your science teacher standing in the hall saying diffraction (the medium is the same).

o

[pic]

o

o interference – happens when two waves meet and the amplitude changes..

o

▪ Constructive interference is when the crest of the combined wave gets higher.

▪ Destructive interference is when the crest of the comgined wave gets lower.

▪ Examples of interference – bright lights, loud noise, etc. are words that imply two waves meeting to produce a higher amplitude.

• Explain how the human eye sees objects and colors in terms of wavelengths

o A prism is a triangle of solid glass that breaks visible light into the colors of the rainbow Roy –G –Biv and the speed of light changes and breaks into different wave lengths.

o So why is the sky blue during the day and red at night?

|Refraction and Reflection in a drop |[pic] |

|since water is more dense than air, light is |Notice you can’t see two colors from one drop because the wavelength of the other colors |

|refracted as it enters the drop- red is bent |don’t come to your eye. Only one wavelength per drop. |

|less, blue more some of the light will reflect|[pic] |

|off the back of the drop if the angle is | |

|larger than the critical angle (48° for water)| |

|the light is then refracted again as it leaves| |

|the drop, the colors of white light have been | |

|dispersed. | |

|blue light will leave the drop at an angle of | |

|40° from the beam of sunlight | |

|red light will leave the drop at an angle of | |

|42° from the beam of sunlight | |

|this process generates the primary rainbow -> | |

| | |

|However, you can not see the blue light and | |

|red light refracted from the same drop!! | |

|So, many drops are involved in producing the | |

|rainbow.... | |

| | |

o Color concepts begin with three basic colors, red yellow and blue.  These are called primary colors.  They are primary colors because they are pure in the sense that the colors are in there most basic form.  They can not be separated into simpler colors.  When you mix all three primary colors together you get brown.   Secondary colors are formed where one color overlaps with another to create a new color.

o [pic]

o

o Long waves are on the left and short waves are on the right. Remember – Make an L with your left hand. ROY B BIV - This means that red is the long wave length and blue is the short wave length. Shorter wave lengths have a higher frequency – meaning they are moving faster. Radio waves are on the far left of the EM spectrum and dangerous “grabba” gamma waves are on the right.

o

o Notice that when all the addative colors or primary colors of light meet, they produce the color white because all the colors are refledcted. When all the subtractive colors or the primary colors of pigments meet, the color black is produced.

o

o Primary colors of light – red, blue, green

o

• Describe how the behavior of waves is affected by medium, such as:

○ air ○ water ○ solids

o EM waves travel the fastest in empty outer space and slow down as the waves go from air to water to a solid.

o

o Mechanical or Sound waves can not travel in empty outer space. Sound waves travel fastest in a solid since the particles are touching. Sound waves get slower going from a solid to a liquid to a gas. Between two solids, sound travels fastest in the one that is least dense.

• Relate the properties of sound to everyday experiences

o Noise is a term often used to refer to an unwanted sound.

o

o Doppler shift with light. An object sending out light moving toward you shifts to blue (shorter wave length) and the light shifts to red when the object is moving away (longer wave length).

o Doppler shift with sound. In front is faster frequency = higher pitch. Behind is slower lower frequency waves = lower pitch.

|[pic] |[pic] |

o An echo (plural echoes) is a reflection of sound,

o

o Soundproofing is any means of reducing the

o

o Soundproofing can suppress unwanted indirect sound waves such as reflections that cause echoes and resonances that cause reverberation.

o

o

▪ Fundamental tone - the fundamental tone is the lowest wave frequency for an object.– The first wave below is the fundamental tone. The others are overtones.

▪

▪ [pic]

▪

▪ c.

• Explain how the parts of a wave are affected by changes in amplitude and pitch

o If amplitude changes then crest and trough change. Higher amplitude means a wave has more energy and the crest is higher and the trough is lower. Sound becomes louder with higher amplitude.

-

o Amplitude is when I move my hand up higher (louder or more energy) and lower (quiet and less energy) when holding a rope.

o

o Frequency is when I move the rope up and down faster (high pitch or high frequency.) or slower (low pitch or low frequency).

-

• Identify the parts of a wave using a diagram

TTTransverse wave - crest, trough, rest position, amplitude (going up or going down), wave length, nothing

Loooongitudinal wave – rarefraction, compression, wavelength.

[pic]

Reflecting Telescope – remember reflecting needs a mirror. Here is the hubble telescope. Notice the eye piece is in the middle.

Refracting telescope – the light comes straight through and the eye piece is at the end of a tube.

Energy can be neither created nor destroyed. Just transformed.

[pic]

[pic]

[pic]

Convex to the person look at this. – The rays spread out as they go through the lens making it look larger.

[pic]

Concave – to the person looking at this. The rays come together making it look smaller.[pic]

[pic]

Above – Pressure goes up and temperature goes up because there are more collisions.

|[pic] | |

| |The cold is more dense because the particles are |

| |moving slower. This means there is more |

| |gravitational attraction and more cold molecules |

| |are pulled into the same area. |

| | |

| |The warm air has more energy so some of the |

| |particles move to another area. |

|[pic] | |

| |The bottom hole has the most water pressing down on it so it comes out|

| |faster. |

| | |

| |The top hole only has a little water pressing on it so it comes out |

| |slower. |

|[pic] |Pressure is a force spread out over a surface. Weight is a force. |

| |Compare the high heals to wearing tennis shoes or even snowshoes. With|

| |high heals, there is the smallest surface area so there is the |

| |greatest pressure. |

|[pic] | So why doesn’t the ballon pop. The balloon would pop on a single |

| |nail because the pressure would be so stron. Since the balloon is |

| |pressing on so many nails, there is less pressure and it does not pop.|

The diagram below is a hydraulic lift.

|[pic] |Remember pressure = force divided by surface area. So the larger the|

| |surface area the more force I need to change the pressure. |

| | |

| |Inside the fluid all the pressure is the same. |

| | |

| |Since the car is on a large surface area a lot of force is needed. On |

| |the other side, there is only a small surface area so a small force is|

| |needed. |

Bernoulli's principle demonstration. (a) A person holds two curved sheets of paper The pressure between the sheets in (b) is lower than the surrounding pressure causing the sheets to get closer. (c) The same result is obtained by using a single sheet. The pressure above the sheet in (d) is lower than the pressure below, thus causing the sheet to lift.

[pic]

|[pic] | |

| |Where the air flows, there is less pressure because there are less |

| |molecules at a given instant. So the air pressure outside the cans is|

| |greater and they are pushed together. |

| | |

| |See the next diagram. |

[pic]

What is happening on the distance/time graph. How do you know that.

[pic]

What is happening on the speed/time graph? How do you know that?

Speed vs. Time Graph

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