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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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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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Chemistry- 3
One of our classmate asked this: What's the difference between bio-hazardous and poisonous?  Ans: biohazard- a hazardous substance that may hurt/kill you that is made by living organisms (eg. blood, semen, mucous, bacteria, viruses)  poison- substances that cause disturbances in organisms. (eg. cyanide) cyanide can kill you by inhibiting the synthesis of ATP in the mitochonrial matrix. When no ATP is made you have no energy to perform any actions including the pumping of your heart as your body solely relies on ATP for power. Fats, sugars, or proteins cannot run your body. ----------------------------------------------------------------------------------------- Chemistry- 2
Miss Liang talked about Forensic science in the first lesson. I thought it was interesting and I did some research on it(:Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. This may be in relation to a crime or to a civil action. Forensic science: -DNA--> blood samples can be sent to SGH. -toxicology department -Handwriting -Force of Impact -Speed of the car travel- this would come to use during a car accident. Forensic science involves physics too! It can determine which direction a person is being stabbed, and it can also determine the force of the attack by looking at the pattern that the blood is being splattered. By using chemistry methods, we can use different methods to analize it. reference source: http://en.wikipedia.org/wiki/Forensic_science Chemistry- 1
Question: What is the tallest building in the world?  According to wikipedia, the tallest building in the world is currently in Taipei. Which is the Taipei 101 (台北101大楼) . This spectecular building is 509.2m tall.  However, the tallest structure of the world is located in Dubai, Burj. It does not currently hold the official title of "Tallest Building in the World" until the building is officially opened. The height of this building would be: 818m, 2684 feets tall. Now now, what's the tallest building in Singapore? &There are 3 buildings in Singapore sharing the title: "The tallest building in Singapore" Isn't it cool? (: Ok, let's check it out!  -UOB Plaza 1 -Republic plaza -OUB Centre OUB Centre was the tallest building outside North America from 1985 to 1988. reference: http://en.wikipedia.org/wiki/Tall_buildings_in_Singapore EXTRA!!! Do you know Singapore Flyer's ranking among the tall buildings in the world? It's 35th! (: Physic- 36
Why aren't there penguins at the north pole?I've got this answer from the net: This is so as there's no land at the north pole and the ice melts and constently moves around. Why penguins don't live with polar bears? Penguins are fabulous swimmers but they’re rather slow and awkward on land. Nonetheless, they spend considerable lengths of time on land during the breeding season, remaining for long periods in the colony. Fortunately, there are few predators on the southern islands or the beaches and ice of Antarctica. In the north, it would be different—in the north, there are Polar Bears, Arctic Foxes and other predators, including people. Any penguin colony that started up in the Arctic would likely quickly fall prey to these carnivores. Indeed, the few human attempts to establish penguin colonies in the Arctic have all failed.Read more: "North Pole Penguin: Why Don’t Penguins Live in the Northern Hemisphere?" - http://bird-habitats.suite101.com/article.cfm/north_pole_penguin#ixzz09LG3jJe7 source: http://wiki.answers.com/Q/Why_aren't_there_any_penguins_at_the_North_Pole Physic- 35
We did some case studies yesterday.Case study 2--> Who drank my lime juice? According to this question, heat is definitely the 'culprit'. Heat from the sun and the surroundings would cause the lime juice in the cup or bottle to evaporate. Therefore, the volume of the water 1 hour later would have a slight different from the initial volume. ---------------------------------------------------------------------------------- Water contracts till it reaches 4 degree Celsius. ---------------------------------------------------------------------------------- Some thing to note about: The atoms in the water does not grow smaller nor grow bigger. The atoms just spaced out or attract to each other even more closely. ----------------------------------------------------------------------------------- In scientific terms, is there really something called 'cold'? Actually, there isn't. It's just more heat or less heat. The word 'cold' is just a word that we normally use. What's the defination of coldnest when it's 0 degrees celsius? There's no defination to it, it's just less heat. No such thing as cold. Physic- 34
Heat:Heat is a form of energy that can move from the hotter object to the colder one. The temperature of the cooler object rises while that of the hotter one falls until both are at the same temperature. Three methods of heat transfer are: 1) Conduction 2) Convection 3) Radiation Heat is a form of energy. Light is also a form of energy. Scientist mentioned that energy can only travel through medium, but not vacuum. Then how did the sun's energy reach us? Well, it is through radiation. Actually, this is quite a good news, isn't it? I say that because, if we were to imagine if the outer space were not vacuum, and were to be filled with all sorts of medium, then heat and light energy would be able to travel through space and reach earth really quickly. And because of that, water on the earth would evaporate even faster and we human beings and all sorts of living things on earth would dehydrate at a high rate. In the end, we would all die of dehydration. Yes, so, having a vacuum in space is not such a bad idea. (: --------------------------------------------------------------------------------- The movements of the hot and cold air moves through convection. Convection currents are set up which transfer heat from the hotter region to the colder regions. What is radiation then? Radiation is the transfer of energy through vacuum in the form of waves. -------------------------------------------------------------------------------------- Note: All hot objects gives out energy as radiation. The radiation moves in all direction. Radiation itself is not hot, but when absorbed. is change when heated. All objects are able to absorb radiation. --------------------------------------------------------------------------------------- Physic- 33
I took these questions from the discussion forum. I shall answer them here(: 1)When certain materials are heated why do some melt & some burn? Ans: Materials with carbon in them will burn. Material without carbon will melt. 2) Why does freezing always start with the surface? Ans: I would say that freezing would start at the surface because heat loss takes time. Meaning it will take longer for the center to reach freezing temperature than the surface. 3) Why does water expand when frozen or when its temperature is below 4 degrees Celsius? Ans: It has something to do with the polar city of the water molecule and the shape of the water molecule. 4) Why does iron turn red after heated? Ans: Everything radiates thermal radiation. The frequency of the radiation for different substances will change with change temperature. Iron turning red hot simply means that its blackbody spectrum is in the visible light wavelengths for a certain range of temperatures ------------------------------------------------------------------------  According to Wikipedia, polar city is a proposed sustainable polar retreat designed to house human beings in the future, in the event that global warming causes the central and middle regions of the Earth to become uninhabitable for a long period of time. Although they have not been built yet, some futurists have been giving considerable thought to the concepts involved. High-population-density cities, to be built near the Arctic Rim and in Antarctica, New Zealand, Tasmania, and Patagonia, with sustainable energy and transportation infrastructure, will require substantial nearby agriculture. Physic- 32
About the Tacoma Bridge: The original Tacoma Narrows Bridge opened on July 1, 1940 and dramatically collapsed into Puget Sound on November 7 of the same year. The suspension bridge spanned the Tacoma Narrows strait between Tacoma and the Kitsap Peninsula. Its replacement was opened in the same location in 1950, and a second, parallel bridge opened in 2007. The instability in winds earned the nickname Galloping Gertie. The bridge's collapse had a lasting effect on science and engineering. In many physics textbooks the event is presented as an example of elementary forced resonance with the wind providing an external periodic frequency that matched the natural structural frequency, even though its real cause of failure was aeroelastic flutter[1] . Its failure also boosted research in the field of bridge aerodynamics/aeroelastics, the study of which has influenced the designs of all the world's great long-span bridges built since 1940. ------------------------------------------------------------------------------------The Tacoma bridge now:  I've uploaded a black and white video in the videos column, do check it out! (: Physic- 31
I've post something about the black body on the discussion forum just now. I saw something like the Planck's Law. Some information about it:For a general introduction, see black body. In physics, Planck's law describes the spectral radiance of electromagnetic radiation at all wavelengths from a black body at temperature T. As a function of frequency ν, Planck's law is written as:[1] This function represents the emitted power per unit area of emitting surface, per unit solid angle, and per unit frequency. Sometimes, Planck's law is written as an expression u(ν,T) = πI(ν,T) for emitted power integrated over all solid angles. In other cases, it is written as u(ν,T) = 4πI(ν,T) / c for energy per unit volume. The function I(ν,T) peaks for hν = 2.82kT.[2] It falls off exponentially at higher frequencies and polynomially at lower. Source: http://en.wikipedia.org/wiki/Planck's_law Sophia. Physic- 30
Questions on Thermal Physics:1) A piece of metal of mass 0·2kg is heated to a temperature of 200°C. It is then put into 0·2kg of water at 20°C in a container of negligible heat capacity. The "final" temperature, after stirring, is 40°C. Calculate the specific heat capacity of the metal. 2) A piece of metal of mass 100g, has a temperature of 100°C. It is put into 100g of water at 20°C in a container of negligible heat capacity. After stirring, the maximum temperature of the "mixture" (metal and water) is 27·5°C. Calculate the specific heat capacity of the metal. 3) How long will it take to change the temperature of 200kg of water from 15°C to 40°C, using a heater of power 3kW. Assume that all the thermal energy remains in the water. Specific heat capacities:
Specific latent heat of fusion of ice = 3·3×105Jkg-1 Molar heat capacities of a diatomic ideal gas: Cv = 12·5J(molK)-1 and Cp = 20·8J(molK)-1 Physic- 29
Thermal physics, generally speaking, is the study of the statistical nature of physical systems from an energetic perspective. Starting with the basics of heat and temperature, thermal physics analyzes the first law of thermodynamics and second law of thermodynamics from the statistical perspective, in terms of the number of microstates corresponding to a given macrostate. In addition, the concept of entropy is studied via quantum theory. A central topic in thermal physics is the canonical probability distribution. The electromagnetic nature of photons and phonons are studied which show that the oscillations of electromagnetic fields and of crystal lattices have much in common. Waves form a basis for both, provided one incorporates quantum theory. Other topics studied in thermal physics include: chemical potential, the quantum nature of an ideal gas, i.e. in terms of fermions and bosons, Bose-Einstein condensation, Gibbs free energy, Helmholtz free energy, chemical equilibrium, phase equilibrium, the equipartition theorem, entropy at absolute zero, and transport processes as mean free path, viscosity, and conduction.[2] http://en.wikipedia.org/wiki/Thermal_physics - sourcePhysic- 28
What is Thermal Physics? Thermal physics is the combined study of thermodynamics, statistical mechanics, and kinetic theory. This umbrella-subject is typically designed for physics students and functions to provide a general introduction to each of three core heat-related subjects. Other authors, however, define thermal physics loosely as a summation of only thermodynamics and statistical mechanics.[1] *Above is a picture heat pumps.*MORE:  <---A heat pump or fridge can be represented by a similar diagram to the one used for the heat engine but with the arrows representing energy flows reversed.Sources: http://www.saburchill.com/physics/chapters/0126.html http://en.wikipedia.org/wiki/Thermal_physics |
