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so sleep alone tonight
My name is ღ||汇嘉||SOPHIAღ. Give me presents! On 22061996 :D [Cancer] [CHRISTIAN] PLMGSS 2.1 I love Aaron (: |
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about this blog
This blog was opened by (SOPHIAARON) to accomodate (SOPHIA)'s Science journal.Do enjoy your stay here, and don't take what's not yours! tagboard
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DORCAS!!!(: MELISSA LISA LISHAN RACHEL RADIENT JANELLE JASLEY SEOWHWEE STELLA STACEY SARAH SHIYU JOYI Bue. Bue. Bue. archives
Videos. (:
-------------Physics------------Liquifaction. How to get out of a quicksand. Math Definitions : What Is Terminal Velocity. Newton's 3 laws of motion. Titration Technique using a burette How to use a pipette. Indroduction to Frictional force. Tacoma Bridge Collapsed! ---------------Chemistry---------- Forensic Video Periodic table song(: Crystal structures: graphite and diamond Chromotography- Separation of MIxtures Separation: Iron from Salt & Sand Mixture Steam Distillation Fractional Distillation Video Video Video Video Video Video Video Video Video Video Video Video Video credits
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Physics 19
Have you ever wondered how we could see the images in the telescope so extraordinarily? Well, this may be the answer to your question! (: Physics 18
Hey all (: I found this interesting and creative song on youtube. Do check it up (:Physics 17
The Ohm's Law
According to wikipedia, Ohm's Law is basically the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them. The equation of the ohm's law:  Let's take a look at a video that summarises Ohm's law (: References: http://en.wikipedia.org/wiki/Ohm's_law Physics 16
Wet cell and dry cells? What are the difference?  This is an example of a wet cell. While this is an example of a dry cell.So, what's the difference then, you may ask. Basically, wet cell is a battery that contains chemical acids which are in liquid state while dry cell contain chemicals that are in dry state (: Therefore from their names, we can simple guess what they really are (: Pictures taken from: google image
Physics 15
A video explaining more about conventional current flow and electrons flow.Physics 14
I asked Mr Lim why conventional current flows from positive from negative instead of negative to positive earlier. What's the difference?I did some research on it and I found a pleasant answer: Electrons are negative and flow from negative to positive. 'Conventional' current flow is from positive to negative. This is because early researchers in electricity thought electricity flowed from positive to negative, which is why they called them that in the first place. And because of this, the 'whole' world thinks that electric current flows from positive to negative terminal. Since the 'whole' world perceives it as that way, we are learning it that way. Well, it's still rather confusing though, sigh. :P reference: http://answers.yahoo.com/question/index?qid=20080205193954AANcXw4
Physics 13
What is refractive index???Ans: The refractive index (or index of refraction) of a medium is a measure of how much the speed of light (or other waves such as sound waves) is reduced inside the medium. For example, typical soda-lime glass has a refractive index close to 1.5, which means that in glass, light travels at 1 / 1.5 = 2/3 the speed of light in a vacuum. Two common properties of glass and other transparent materials are directly related to their refractive index. First, light rays change direction when they cross the interface from air to the material, an effect that is used inlenses. Second, light reflects partially from surfaces that have a refractive index different from that of their surroundings. http://en.wikipedia.org/wiki/Refractive_index
Physics 12
One common mistake that we people all make:Light travels into our eyes, our eyes do not give out light. Well, you can simply look into each other's eyes to check if our eyes are glowing (: If they are, your friend is the first known light source friend (: Physics 11
This is a video of white light dispersion. Physics 10
Why is red colour of the dispersed white light on the top, while the violet on the bottom of the rainbow? The reason is that red light travels at a faster speed than the violet light. Therefore, the red light will bent away from the normal. The violet light travels at a slower speed than the red light, and therefore will bend towards the normal. Hence, the red light will appear to be on top of the rainbow while the violet will be at the bottom.
Physics 09
Mr Lim told us that there's solar eclipse today at the Indian Ocean. Singapore will feel the after effect around 3.10pm this afternoon. Too bad I missed it ): What is solar eclipse then?    A solar eclipse occurs when the moon passes between the Sun and the Earth so that the Sun is fully or partially covered. This can only happen during a new moon, when the Sun and Moon are in conjunction as seen from the Earth. At least two and up to five solar eclipses can occur each year on Earth, with between zero and two of them being total eclipses. Total solar eclipses are nevertheless rare at any location because during each eclipse totality exists only along a narrow corridor in the relatively tiny area of the Moon's umbra. A total solar eclipse is a spectacular natural phenomenon and many people travel to remote locations to observe one. The solar eclipse of August 11, 1999 in Europe helped to increase public awareness of the phenomenon, as illustrated by the number of journeys made specifically to witness the total solar eclipse of October 3, 2005 and the total solar eclipse of March 29, 2006. The recent solar eclipse of January 26, 2009, was an annular eclipse (see below), while the solar eclipse of July 22, 2009 was a total solar eclipse. The next annular event is the Solar eclipse of January 15, 2010 and the next total event is the solar eclipse of July 11, 2010. In ancient times, and in some cultures today, solar eclipses have been attributed to supernatural causes. Total solar eclipses can be frightening for people who are unaware of their astronomical explanation, as the Sun seems to disappear in the middle of the day and the sky darkens in a matter of minutes. http://en.wikipedia.org/wiki/Solar_eclipse Physics 09
I found this on Yahoo, and thought it's kind of interesting. The title is "Top 10 ways to Destroy Earth". Here's the link (: Check it out. Physics 09
And, I found some interesting facts about refraction.It's called the Refraction and the Eye and the Sound refraction. Check it out, I'll be posting it to my side links (:
Physics 08
Next, is refraction.We just finished the topic on refraction today so it is quite fresh in my mind. Refraction is the bending of light due to the change of direction. Usually, refraction takes place in the change of mediums when the speed of light travels from a less dense to a more dense or a more dense to a less dense place. Because of this, the speed of light will change due to the different mediums. So, when light is traveling from a less dense medium to a more dense medium, say from air to water, the light ray will get refracted. The light ray will bend towards the normal when it enters the more dense medium, and when it enters the less dense medium, the speed of light will increase, causing the refracted ray to bend away from the normal.  Hence, to conclude: Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law. reference: My brain, textbook, http://hyperphysics.phy-astr.gsu.edu/Hbase/geoopt/refr.html
Physics 07
Basically, for the past few lessons, we've learning reflection and refraction.What about reflection? Objects can be seen by the light they emit, or, more often, by the light they reflect. Reflected light obeys the law of reflection, that the angle of reflection equals the angle of incidence.  The light ray that emits from an object is called the incident ray. While the reflected image from a surface is called the reflected ray. There is a normal, which is perpendicular to the surface. Take note that the angle of the incident ray is = to the angle of reflected ray. Most objects exhibit diffuse reflection, with light being reflected in all directions. All objects obey the law of reflection on a microscopic level, but if the irregularities on the surface of an object are larger than the wavelength of light, which is usually the case, the light reflects off in all directions. PLANE MIRRORS: A plane mirror is simply a mirror with a flat surface; all of us use plane mirrors every day, so we've got plenty of experience with them. These are the properties of the reflected image: 1) The image is upright 2) The image is laterally inverted 3) The object from the mirror, is = to the mirror from the object in the mirror. 4) The image is virtual 5) The image will be the same size, colour etc  ------------------------------------------------------------------------------------------------------------ Apart from plane mirrors, we also have concave and convex mirrors. What are concave mirrors then? Basically, concave mirrors are mirrors that bend inwards.  Hence, the mirror image will appear larger than it actually is. How about convex mirrors? Convex mirrors are mirrors that bend outwards.  Which means, it can reflect image from a larger distance into our eyes. Hence, it's use commonly as blind spot mirrors. Physics 06
Today during lesson, Mr Lim flashed a slide on the Snell's law.I didn't quite get the formulae on the screen. Here are some of the description on Snell's law: In optics and physics, Snell's law (also known as Descartes' law, the Snell–Descartes law, and the law of refraction), is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water and glass. The law says that the ratio of the sines of the angles of incidence and of refraction is a constant that depends on the media.
In optics, the law is used in ray tracing to compute the angles of incidence or refraction, and in experimental optics and gemology to find the refractive index of a material. Snell's law is also satisfied in the metamaterials which allow light to be bent "backward" at a negative index, with a negative angle of refraction. Named after Dutch mathematician Willebrord Snellius, one of its discoverers, Snell's law states that the ratio of the sines of the angles of incidence and refraction is equivalent to the ratio of velocities in the two media, or equivalent to the opposite ratio of the indices of refraction: or Snell's law follows from Fermat's principle of least time, which in turn follows from the propagation of light as waves.
Above are taken from http://en.wikipedia.org/wiki/Snell's_law
Summary:
Snell's law gives the relationship between angles of incidence and refraction for a wave impinging on an interface between two media with different indices of refraction. The law follows from the boundary condition that a wave be continuous across a boundary, which requires that the phase of the wave be constant on any given plane, resulting in Physics 05
Are sports drink acidic?Sports drinks commonly contain citric acid. All acids have an erosive potential but the method of drinking will influence whether or not those acids affect the teeth. Sports drinks should be consumed as quickly as possible, preferably with a straw and not be held or swished around the mouth. Retaining drinks in the mouth will only increase the risk of erosion. Refrigerated drinks will have a reduced erosive potential, as the acid dissolution constant is temperature dependant. http://www.brianmac.co.uk/drinks.htm Physics 04
To some of you, you may ask, what is glycerine, is it poisonous? According to wikipedia, glycerine is a common named used. It is supposed to be called glycerol. It is an organic compound, It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopicnature. The glycerol substructure is a central component of many lipids. Glycerol is sweet-tasting and of low toxicity. http://upload.wikimedia.org/wikipedia/commons/c/c7/Glycerol-3D-balls.png http://en.wikipedia.org/wiki/Glycerol
Physics 03
I'm back with another question:Situation: Mr Lim put a test tube into a boiling tube. Then he poured glycerine into the boiling tube. Yes, the glycerine filled up both the test tube and boiling tube. Guess what? the test tube 'disappeared' after the glycerine filled both tubes! Why is this so? Below are some explanations to the question. Explanation : We see edges of objects because light is either reflected or refracted at their boundaries. In case of clear objects, such as glass and some plastics, refraction allows us to discern them from the surrounding. Water and glass have different indices of refraction, which makes the light bend at the boundaries of the two material. This makes the sides of the submerged test tube visible when held under water. When a test tube is submerged under glycerine, however, will not be visible as glycerine and the Pyrex glass have the same index of refraction. Which means that, light is not refracted at all when it crosses boundary with the glycerine and the glass. Therefore, when Mr Lim submerged the test tube with glycerine, the test tube simply disappears (: Well, to summarise everything up, light was no reflected as both glycerine and test tube has the same index of refraction. reference: www.physicscentral.org/experiment/physicsquest/.../pq06-Extension4.pdf
Physics 02
Okay, today in class, Mr Lim asked us blog about two questions. I'm going to do the first one in this post. Question: Why do ice stick to our finger. From my personal experience, the ice doesn't stick to our finger every single time. I'm not sure how it happens too. But I do noticed that the ice cubes tend to stick to our finger when our fingers are wet, or when we use our tongue. Let's find out why (: According to a website named The Naked Scientist, it explains that this is because the ice then re-freezes the liquid on your finger. And, the fact is, the ice cube doesn't get stuck to us, we get stuck to it. Interesting? Because the liquid is a fluid and it has got into all the nooks and crannies on your finger it then freezes solid and will form a very tight bond between your finger and the frozen surface, the ice. You get stuck to the surface. If it’s an ice cube –it’s okay because there’s enough heat flowing through your fingers However, those eskimos living in Antartica might not be that lucky. Because their temperature is c.-70 degree celsius, once they get stick to the ice, it might be permanent and might not be able to remove it. If not, the eskimo might get an serious injury from the ice. This is so as their body doesn't warm up. reference: http://www.thenakedscientists.com/HTML/content/questions/question/2265/ That's why ice are sticky (:
Physics 01
Hi all, I'm back. After 7 months. Sorry for being lazy. :p Happy New Year, I know it's late. Back here to start the journalling exercise again. Just like last year. |
