William

**Physics project**
I will be researching and talking about the refraction of waves, what is it, what causes it, and many more.

What's a refraction? I don't know, you tell me. A refraction is the bending of a wave when it enters a medium where it's speed is changes; when the wave or light passes from a fast medium to a slow medium, it bends the light ray towards the 'normal' the line between the two media which is suppose to be 'normal'. The amount of bending depends on the [|index of refraction] , to find the index of refraction, we take the speed of light in vacuum divided by the speed of light in the medium in which it passes trough: n=c/v Refraction can also be define as the transmission of wave or light between two different boundaries. When a wave or light hits a boundary at a angle, the light gets bended and the wave gets transmitted into the new medium, but since the subject of the new medium is different, it gets bended, or refracted. Example: The refraction of light waves. When light wave travels, it goes on straight forever, but when it hits a boundary like glass, part of the light gets reflected and part of it gets refracted. But how does the refraction occurs? When the light waves reaches the glass boundary, the speed and wavelength changes, so the direction of the light changes at a angle. http://www.physics.uoguelph.ca/applets/Intro_physics/refraction/LightRefract.html, this is a link to test and see the refraction of light through different boundaries.
 * REFRACTION**

Speed and velocity have differenet meanings: When you talk about speed, your talking about how fast a object is moving where in the pther hand velovity means how fast a object changes its position. For example, a ball rops and bounces back, it drops and bounces back, eveytime it drops, it bounces back to the same position it was dropped (even though it's not possible) The speed equation equals to the difference of the distance over time. Speed= Disctance/Time. The wave equation is: velocity=frequency x Wavelength.  

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**__Properties of a wave__**   =====  

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<span style="font-family: 'Times New Roman',Times,serif"> <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal"> <span style="color: rgb(72, 40, 40)">period: the time it takes for one complete wave to pass a given point, measured in seconds. <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal">  =====

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<span style="font-family: 'Times New Roman',Times,serif"> <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal"> <span style="color: rgb(72, 40, 40)">trough: The lowest point of a wave form the rest position. The maximum amount of downward displacment from the rest position. ·<span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal">  =====

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<span style="font-family: 'Times New Roman',Times,serif"> <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal"> <span style="color: rgb(72, 40, 40)">wavelength: the lenght of one complete wave or wave cycle. The distance between adjacent crests. <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal">  =====

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<span style="font-family: 'Times New Roman',Times,serif"> <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal"> <span style="color: rgb(72, 40, 40)">amplitude: the distance from the rest position to the crest or to the trough  <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal">   =====

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<span style="font-family: 'Times New Roman',Times,serif"> <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal"> <span style="color: rgb(72, 40, 40)">frequency:the number of complete waves that pass a point in one second, measured in or **Hertz** (Hz). <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal">  =====

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<span style="font-family: 'Times New Roman',Times,serif"> <span style="font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal"> <span style="color: rgb(72, 40, 40)">crest: The highest point of a wave from the rest position. The maximum amount of upward displacement. =====

There are many kinds of waves, but all the properties listed above exist in every kind if waves, this is important, so let me repeat it: __The properties listed above exist in all kinds of waves__. The 5 major kinds of waves are longitudinal waves, transverse waves, electromagnetic waves, surface waves and mechanical waves. <span style="color: rgb(6, 234, 133)"> Longitudinal: The particles of a longitudinal waves move parallel to the direction of the waves.The section of a longitudinal waves which is pressed together is called Compression; the other section which the layersare spaced because of the time lag is called Rarefraction.The section of a longitudinal waves which is pressed together is called Compression; the other section which the layers are spaced because of the time lag is called Rarefraction. Transverse: The particles of the medium of this wave moves perpendicular to the direction of the wave. <span style="color: rgb(22, 233, 173)"><span style="color: rgb(10, 245, 166)">The particles do not move along with <span style="color: rgb(10, 245, 148)">the wave; they simply oscillate up and down about their individual equilibrium positions as the wave passes by. <span style="color: rgb(6, 234, 133)"> Electromagnetic:<span style="color: rgb(13, 222, 132)"> <span style="color: rgb(13, 222, 132)">Electromagnetic waves are waves that can transmit energy or travel through a vacuum or empty space. Electromagnetc waves are produced from the vibration of electrons and chraged particles. Examples of electromagnetic waves are light and sunlight. <span style="color: rgb(6, 234, 133)"> Surface: Surface waves is the mixture of some longitudinal and some transverse waves. The particles of this wave undergo a circular motion; there is a slight difference between surface waves and 'longi-transverse' waves, it's that in a surface wave, only the particles on the surface of the medium undergoes the circular motion. <span style="color: rgb(6, 234, 133)"> Mechanical: A wave that is not capanble of transmitting energy through a vacuum. Mecahnical waves requires a medium so it could travel, longitudinal, transverse, surface waves, are all catagories of mechanical waves.

Pressure: A wave that consists of repeating patterns of both high pressure and low pressure waves. Thie is called a pressure wave. Sound ofr example is a pressure wave. The index of refraction tells us the amount of bending the wave is. The equation for the index of refraction is the speed of light in vacuum divided by the speed of light in the medium. Another thing that is also notable is "__Snell's Law__". Snell's law is the formula to describe the relationship between the angle of incidence and refraction, which in this case referring to a wave or light traveling through a different boundary or medium. The snell law is often used in testing optic refractions, usually to find the material's __<span style="color: rgb(15, 162, 6)">index of refraction __. The formula for Snell's law is this: , and  are the angles from the //normal// of the incident and refracted waves The indices of refraction for some common substances are below: +Water-->1.33 + Ice-->1.31 + Vacuum-->1.0000 + Sugar solution 30%-->1.38 + Salt(Sodium Chloride)-->1.544 + Ethy alcohol --> 1.36 I will do a project for light refraction. I would need a transparent tank or container to test, *The detailed procedure would be updated later on, when the experiment is done* First experimenting it with plain water Second I experimented it with salt water Later, I'll be experimenting it with, sugar and Ethyl alcohol Physics rock The experiment turned out to be different with the formula of the indices of reafraction. The index of refraction for Sodium Chloride is suppose to be bigger, meaning the amount of refraction should be greater than any other substance listed above.
 * Project---**

<span style="color: rgb(0, 1, 138); font-family: 'Comic Sans MS',cursive">**How I did my experiment?**
My project is about the refraction of light, my materials are the following: Laser pen, small plastic container(tank), water, and the materials you want to mix with, in my case I have ethyl alcohol, sugar, and salt. <span style="color: rgb(4, 13, 134)"> __THE PROCEDURE__ <span style="font-family: Georgia,serif">starts with pouring warm water into the plastic tank, then shine the laser from one side of the tank to another in a dark room to check out the refraction. Next, go add some table salt into the water and mix it until it gets saturated, then go into the dark room again and shine the laser from at the container. I repeated the same steps except with different substance added into the water to create a different medium. <span style="color: rgb(4, 169, 42); font-family: Verdana,Geneva,sans-serif; background-color: rgb(245, 137, 137)"><span style="color: rgb(64, 180, 4); font-family: Verdana,Geneva,sans-serif; background-color: rgb(227, 69, 69)"> Any thoughts: However, in my experiment, the light through ethyl alcohol bends more than salt water. The problem might belong to the amount of alcohol added, there's 100ml of ethyl alcohol and it blends withe water perfectly, the salt however, covers maybe less than 40% of the water, I should've made it supersaturated (unable to saturate anymore) to see the big difference. Overall, I think my project is pretty successful, I got to see the refractions of the light through different medium. What's really difficult is to draw the refraction ray accurately, we can't see it through water, we need a peice of paper underneath it.

<span style="color: rgb(237, 38, 38); font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif"><span style="color: rgb(226, 34, 37); font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif"> In the Image: <span style="color: rgb(79, 74, 74); font-family: Tahoma,Geneva,sans-serif"><span style="color: rgb(105, 93, 93); font-family: Tahoma,Geneva,sans-serif">Pencil-ray in wate r, <span style="color: rgb(0, 0, 0); font-family: Tahoma,Geneva,sans-serif">black pen-ray in salt water , <span style="font-family: Tahoma,Geneva,sans-serif; background-color: rgb(157, 252, 69)">black pen with highlighter(zoomed in)-sugar water, <span style="color: rgb(4, 28, 159); font-family: Tahoma,Geneva,sans-serif">blue pen-70ml alcohol , <span style="color: rgb(221, 8, 8); font-family: Tahoma,Geneva,sans-serif">red pen-100ml alcohol

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[|IMG_0218[1]] <span style="color: rgb(56, 14, 149); font-family: Impact,Charcoal,sans-serif"><span style="color: rgb(30, 3, 155); font-family: Impact,Charcoal,sans-serif"> <span style="color: rgb(237, 38, 38); font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif"><span style="color: rgb(226, 34, 37); font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif"><span style="color: rgb(56, 14, 149); font-family: Impact,Charcoal,sans-serif"> ***I chose to link this image because you can zoom in and zoom out in the image.**  =====

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<span style="color: rgb(56, 14, 149); font-family: Impact,Charcoal,sans-serif"><span style="color: rgb(237, 38, 38); font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif"><span style="color: rgb(226, 34, 37); font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif">**That will make the thin lines clearer to you***  Please click on the link.===== <span style="font-size: 130%; color: rgb(240, 193, 45)">

<span style="font-size: 140%; color: rgb(244, 216, 37)">WAVE EXPERIMENT : <span style="font-size: 120%; color: rgb(8, 247, 245); font-family: Tahoma,Geneva,sans-serif; background-color: rgb(10, 62, 184)"> <span style="color: rgb(0, 0, 0)"> Hello Chicos y chicas, boys and girls, The following information would be about me and Hyun Woo's experiment with diffraction. Before getting into the details of the experiment you first have to define the word **Diffraction**. <span style="color: rgb(15, 234, 11); font-family: 'Courier New',Courier,monospace">Diffraction:<span style="font-size: 10pt; color: rgb(22, 248, 13); font-family: 'Courier New',Courier,monospace">refers to the bending of waves when they interact with obstacles in their path. It occurs with any type of wave, including sound waves, water waves, and electromagnetic waves such as visible light etc. ; the diffraction of waves usually has the most effect on the wavelength of the wave. The final ‘product’ of the diffracted waves are resulted from the interference between different parts of a wave that traveled through a different path. For example diffracted light can be spread out on a wall.
 * <span style="background-color: rgb(230, 124, 5)"> Diffraction with WATER** <span style="background-color: rgb(230, 124, 5)"><span style="background-color: rgb(230, 124, 5)"><span style="background-color: rgb(230, 124, 5)">   <span style="background-color: rgb(230, 124, 5)"> William and Hyun Woo

First of all, we wanted to test whether the opening of a single-split would affect the wavelength of the water wave. A single slit is by aligning 2 obstacle but leaving a gap in the middle. Like this: As you can see in the picture, the opening of the obstacle caused the incoming wave to 'spread out' after the gap, the diffraction causes the wave to spread like a ripple, a circular motion. Just as the incoming wave passes through the opening, a little bit of refraction happens, then it starts to bend and spread in a circular motion. <span style="color: rgb(42, 79, 248)">We first started with a instrument that can hold water and produce water waves, a long flat piece of plastic is connected to a stick that vibrates up and down the container(remember that there is water in the container)<span style="color: rgb(64, 0, 255)"> ; when it hits the water, it produces a water wave, because we adjusted the frequency to its highest, the plastic vibrates up and down the container and produces many water waves continuesly.>>>>So the experimnet begins, we placed two plastic block close to the wavefront, and left some space between it, then we turned on the instrument, and it started to produce wave, one the water wave hits the oppening, it appeared to result like the picture above, the water wave starts to spread out in a circular motion, but the wavelength stays the same. Here, the waves are produced, then it gets diffracted while it reaches the two obstacle. Later, we adjusted the frequency to the highest, and it produces a much better image.[|SSL12723.JPG] < This link is to a Full-Sized image, you will be able to really see the diffraction and the wavelength. Next, me and Hyun Woo tried it out with different oppening of the single-slit, it turns out that if the split is larger, the deffracted waves doesn't get so 'roundish anymore' and another thing that we found out is that when the wave gets diffracted, the wavelength actually gets smaller and closer together when it gets further away from the obstacle. Now, we can compare the diffrence in the diffraction of the wave between a large opening and a smaller opening; in the larger opening, the wave seems to get refracted a little bit first before it starts to spread out again, but the angle when it diffracts seems to be small, it doens't really affect the incoming wave that much, the diffracted wave is some what still going straight. But comparing it with the smaller opening, the wave immediately diffracts at a really big angle, and spreads out like a ripple, and recalling what we've discovered earlier, the wavelength seems to get smaller and close together when it starts to reach the end. <span style="font-size: 130%; font-family: Impact,Charcoal,sans-serif; color: rgb(255, 0, 20)"> Now, the best part of the experiment is to take a look at the video which demonstrates the different opening and the different diffraction angle. <span style="color: rgb(0, 0, 0)">This is our results of the experiment, video taped. <span style="color: rgb(42, 79, 248)">media type="youtube" key="-LtQrnYAZas" width="472" height="391"

<span style="color: rgb(42, 79, 248)"> <span style="color: rgb(20, 16, 16)">**AIM:**
To find out whether the opening of a single-slit affects the wavelength

**Materials:**
Wave projecting machine-provided by Mr.Happer Plastic blocks used as obstacles Water Ruler

**Variables:**
Independent variable- The opening of the single-slit Dependent variable- wavelength Controlled variable- amount of water+the frequency

**Procedure:**
1) get the machine and projector ready to work 2). put the machine on the projector, the shadows of the diffracted water would show up clearly on the wall 3).Start taking photos of the outcome, change the opening eveytime 4).Compare the wavelength when the opening of the single-slit changes everytime. 5). record and write down our observation and conclusion

**Conclusion:**
We concluded that the wavelength of the diffracted water wave stays the same throughout the whole experiment, even though theres only a really slight different(because the measurments are not very accurate, the water is moving) but there is really no big difference. The only thing that changes is the direction of the wave and the diffracted wave's angle, the angle that the wave diffracted in the bigger opening is much smaller compared to the one in a smaller opening; in other words, the wave spreading of the wave is larger in the small opening. Here is an explanation to that:<span style="font-size: 110%; font-family: Tahoma,Geneva,sans-serif; color: rgb(112, 239, 1); background-color: rgb(5, 32, 153)"> <span style="font-size: 110%; font-family: Tahoma,Geneva,sans-serif; color: rgb(138, 255, 0)">The opening of the single-slit is smaller than the wavelength, and so many waves starts to push towards the opening, the other side of the single-slit is empty, that means that when the waves starts passing the small opening, it causes the pressure to rise up, so one side of the sinlge-slit is high pressure and the other side low. This results in the wave rushing out into the other side in all direction, that's why in the smaller slit you can see that it spreads out in this circular motion. For a opening larger than the wavelength, the opening is somewhat like a invisible thing, the wave just passes through; to the waves, there is 'barely' any obstacle in their way, that's why the wave proceeds to move through the opening in the the same direction and almost the same pattern.

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