Usage of air pressure

I came across this interesting video by Steve Splanger and wanted to share it. It is about using air pressure to create cloud in an instance.

Non-newtonian fluid

A non-Newtonian fluid is a fluid whose viscosity is variable based on applied stress. The most commonly known non-Newtonian fluid is cornstarch dissolved in water. Contrast with Newtonian fluids like water, whose behavior can be described exclusively by temperature and pressure, not the forces acting on it from second to second. Non-Newtonian fluids are fascinating substances that can be used to help us understand physics in more detail, in an exciting, hands-on way.

Well, I found this video particularly interesting as it shows a comedy show, with a pool filled with non-newtonian fluid. Rather than just a small bowl, why not have a big pool of it! When we run, jump, or even skip on the pool of the non-newtonian fluid, we are applying force on it. Thus, it would harden and as a result, we will not sink! Now let us watch this video of the experiment of floating on liquid.

Newton's first law of motion

Newton's first law of motion :

Every object in the state of uniform motion tends to

remain in that state of motion

unless an external force is applied to it.

Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This is normally taken as the definition of inertia. The key point here is that if there is no net force resulting from unbalanced forces acting on an object (if all the external forces cancel each other out), then the object will maintain a constant velocity. If that velocity is zero, then the object remains at rest. And if an additional external force is applied, the velocity will change because of the force.

Examples : The motion of a ball falling down through the air ; a model rocket being launched up into the atmosphere.

Elements

An element is a substance made of only one atom and cannot be broken down. An element is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons.

In the universe, there are alot of different elements. The most abundant element is Hydrogen, followed by Helium, then Oxygen, Carbon, Neon, Iron, Nitrogen, Silicon, Magnesium and lastly Sulfur.

Uncommon Elements

Berkelium

Berkelium is a member of the actinide group, which comprises the 14 chemical elements with atomic numbers from 90 to 103. Its atomic number is 97 and its symbol is Bk. Its colour is silver. It can be attacked by oxygen, steam and acids but not by alkalines. It is a radioactive element which tends to accumulate in the skeletal system.

Beryllium

Its symbol is Be and its atomic number is 4. It has the ability to scratch glass which is probably due to the formation of a thin layer of the oxide. Although beryllium products are safe to use and handle, the fumes and dust released during fabrication are highly poisonous. Its uses includes for watch spring, space shuttle parts, welding electrodes, X-ray tubes, computer lasers, televisions, oceanographic instruments etc.

Bismuth

Its symbol is Bi and its atomic number is 83. It is a white, crystalline, brittle metal with a pinkish tinge. Bismuth's thermal conductivity is lower than any metal, with the exception of mercury. It has the highest atomic weight and atomic number among all the nonradioactive elements. Its uses are for fuses, fire extinguishing systems, acrylic fibers etc.

What is a fart and why does it smell?

A fart is a combination of gases (nitrogen, carbon dioxide, oxygen, methane and hydrogen sulfide) that travels from a person's stomach to their anus. When a person swallows too much air or eats foods that the human digestive system cannot digest easily gas becomes trapped in his/her stomach. The only way for this excess gas to exit the body is through the anus.

The gas that makes your farts stink is the hydrogen sulfide gas. This gas contains sulfur which causes farts to have a smelly odor. The more sulfur rich your diet, the more your farts will stink. Some foods that cause really smelly farts include: beans, cabbage, cheese, soda, and eggs.

The word fart is just one of many different terms used to describe the release of gasses from the human body. Other popular names for farts or farting include: gassers, stinkers, air biscuits, bombers, barking spiders, rotten eggs, and wet ones. You can pass gas, break wind, blast, beef, poof, rip one, let one fly, step on a duck, and cut the cheese.

Chemical Reaction

This is another ace project which I have done. This time, I did it using prezi. This is the link : http://prezi.com/ptncyyzgtf84/chemical-reaction/.

Chemical reaction :

• Reaction of two or more elements/compound together
• Formation of a chemical bond between atoms
• Formation of a chemical compound

Six types of reaction :

• Combustion
  
• Synthesis
• Decomposition
• Single displacement
• Double displacement
• Acid-base

I will be focusing on combustion, synthesis and also decomposition.

Combustion :

• The combination of water and other compounds/elements to form water and carbon dioxide
• For example : Burning of wood

Synthesis :

• Two or more compounds/elements form a more complex compound
• For example : Mixture of iron and sulfur to form iron ( ll ) sulfide

Decomposition :

• The seperation of a complex compound into simpler and smaller substances
• Opposite of synthesis reaction
• For example : Use of electrical current to seperate water into hydrogen and oxygen

Diet coke and Menthos

Soda drinks have carbon dioxide gas in them, and this is what makes it bubbly. this carbon dioxide gas stays suspended in the liquid of bottles of soda, until you open and pour it out. mentos consists of sugar and some other things. one of them is called gum arabic, and it makes the mentos chewy.
As mentioned in the video, there are tiny pits on the mentos which produce carbon dioxide gas. this gas is released, along with the extra pressure which cause the carbon dioxide in the soda drinks to break apart faster by the gum arabic when it is finally released, this pressured-gas in soda drinks thrust out of the bottle, bringing the contents along with it.

Now let us watch a video on diet coke and menthos.

Light

I have done this powerpoint on Light for my Ace a while back, so I shall now post it here too.

So basically, light is a form of energy which our sense of sight can detect. It is made of electro-magnetic radiation and travels in a straight path. The speed of light in a vacuum is calculated to be exactly 299,792,458 m/s, which approximately 186,282 miles per second.

Light Waves

• Does not require a medium to travel on. Instead, it travels through a vacuum.
• Consists of energy in the form of electrical and magnetic fields.
• Sizes of light waves are measured by wavelengths. ( Elaborating on that later )

Primary Charateristics of Light

• Intensity
• Frequency
• Wavelengths
• Polarization
• Phase
• Orbital angular momentum

Intensity

• Measure of energy flux, averaged over the period of wave.
• Obtainable by dividing either a power or a luminous flux by a solid angle, a planar area, or a combination of the two.

Frequency

• Number of waves that pass a point in space during any time interval
• Measured in Hertz ( Hz )
• The amount of energy in a light wave is proportionally related to its frequency

Wavelengths

• We can only see electromagnetic waves.
• Each colour has different wavelengths
• Distance between any two corresponding points on successive waves

Polarization

• Expression of an orientation of the lines of electric flux in an electromagnetic field.
• When light reflect from a surface like glass, the light waves polarize, meaning that they travel along an axis usually horizontal. A vertical polarizing lens reduces the brightness of these light waves while still allowing optical information through.

Phase

• In wave motion, the fraction of the time required to complete a full cycle that a point completes after last passing through a reference position.
• Two periodic motions are said to be in a phase when corresponding points of each reach maximum or minimum displacements at the same time.

Term 3 Reflection

How time flies! Three meaningful and interesting term have gone by in a blink of an eye. Science lessons were fun ; going to the lab, making use of particular instruments to do experiments, etc ...

I have learnt a lot from them. However, my science test grades aren't as good as I expected them to be. My current science grades are always getting A2, probably a few more marks from an A1. Perhaps I did not study well enough? This all lies in my own hands.

Anyway, this term I learnt more about photosynthesis, respiration and cells. To start off with cells, Miss Leong went through with us the basic knowledges of parts of the cells that we have learnt in primary school. Also, we were provided with several notes, in which one of them have images of cells with many different other parts of the cells which I suppose many of my classmates, including myself, don't know about.

I have not been doing well for this three terms, so for this last Term 4, I will try my best and get a better result.

Home-Learning: Density

Question: Why does an egg sink in fresh water, and why salt water causes the egg to be able to float?

Answer: As we all know, items will sink when their density is greater than that of what they are trying to float on. The density of the egg is greater than that of the fresh water, thus causing the egg to sink. However, when salt is added to the fresh water, it causes the egg to be more buoyant and it increases the density of the fresh water. As a result, it causes the egg to float in the salt water.