How does a magnifying glass works?

(http://www.calledtocommunion.com/wp-content/uploads/2009/09/magnifying-glass.jpg)

First things first, what is a magnifying glass?
As you can see in the image above, it is a convex lens which is used to produce a bigger image of the object.
An example is that you are trying to read a book.
However, the words are too small for you to see.
Thus, you can use the magnifying glass to magnify to the words, so that you are able to read. The glass is usually shaped in a circle with a handle attached to it for support.

Next, how does a magnifying glass works?
It works by creating a magnified virtual image of the object behind the lens. The distance between the lens and the object must be shorter than the focal length of the lens for it to work.

Source: (http://en.wikipedia.org/wiki/Magnifying_glass)

How does a matchstick be lit up by using a magnifying glass?

(http://www.wildwoodsurvival.com/survival/fire/magnifier/index.html)

The answer is simple.
However, to do this, the focal point of the lens (of the magnifying glass) has to be at the right spot, like the image below. Just make sure that to hold the magnifying glass at the correct distance, so that there will be a huge amount of light going to the tip of the matchstick. The correct distance is when the bright dot is really small and where you can see a full circle on the matchstick.

(http://farm4.static.flickr.com/3063/2730103489_06f117680a_o.jpg)

Physics Graded Assignment (reg 11).

1) How many images would you get for an object that is placed between two mirrors placed at an angle less than 90°?

For example, if the object is placed at an angle of 45 degrees, there will be 7 images reflected. This is because there is a pattern of the smaller the angle is, the more images can be reflected.

2) What happens to the images of this angle is it is bigger than 90°?

As the angle increases, there will be lesser images reflected. Eventually, as the mirrors are 180°which means that it is a single line of mirror, there will only be one image reflected.

3) How do mirrors produce funny images?
 
Mirrors of different shapes have their own effects. An example is that the middle mirror is concave and stretches your image sideways to produce a fat version of you. The mirror on the right is a convex mirror and it produces another version of you. The mirror on the left is a combination of both. Thus, you will see different images of yourself.
 
Sources from:
(http://homepage.mac.com/cbakken/obookshelf/mmirrors.html)
(http://www.science.edu.sg/ssc/detailed.jsp?artid=3418&type=5&root=88&parent=115&cat=200)

Networking Project for Science Chemistry (reg 11).

1 ) Microwaved food is believed to contain microwaves. How safe is microwaved food?

Microwaves can be used to heat up leftovers from yesterday’s dinner or lunch so that the bacteria will die and the food is edible. However, it also has its disadvantages. Microwaves in a microwave oven can deplete the nutrients in food. Of course, it is not at all surprising that microwave heating results in loss of nutrients since most heating methods have the same effect. However, results show that the heating in microwaves have far more greater nutrient loss than other heating methods.

Microwaves may also cause changes in our bodies. For example, once the structure of the food is altered, it is unable to carry out the normal function in our bodies. Another example is that microwave heating of milk results in a decline in haemoglobin levels. Studies have shown that the radiation in which the microwave has can lead to the loss of important nutrients in the breast milk which the newborn baby needs from its mother to protect its body against diseases. Thus, it is not recommended to heat up breast milk for the baby by using the microwave oven. It is also advisable to stay away from the microwaves when in use.

Source from: (http://www.healingdaily.com/microwave-ovens.htm)
Pictures from: (http://top-10-list.org/wp-content/uploads/2009/08/Microwave-Ovens.jpg) & (http://www.electricpig.co.uk/wp-content/uploads/2008/12/radiation-symbol1.jpg)

E-learning assignment Part 3 (reg 11).

Body temperature can be affected by things like extreme physical activity, ovulation and smoking. The temperature cycle is the same between different genders. However, the age does affect the temperature cycle. Studies have shown that older people will sleep tend to wake up more often after they sleep. Older people not only wake at an earlier clock hour, they also wake at an earlier internal phase of the circadian cycle than young people. A normal, healthy person is able to maintain a constant body temperature of approximately 98.6F despite the temperature of the environment and surroundings. Exercising at different times of the day will not affect your body temperature cycle because it will only make your body feel tired and sleep well. There is a correlation between body temperature and concentration, mood and learning. For instance, if the body temperature is not good, the person will get mood swings easily and he or she will not be able to concentrate as well, thus will is unable to learn anything.

Sources:
(http://www.stanford.edu/~dement/temp.html)
(http://www.websciences.org/cftemplate/NAPS/archives/indiv.cfm?ID=19979328)
(http://www.apparelyzed.com/temperature.html)
(http://everything2.com/title/body+temperature)

E-learning assignment Part 2 (reg 11).

What would be the effect if a spaceship landed, and the aliens in it estimate that they are 400 years ahead of us? What would happen if they offered us all their scientific knowledge? Would it be good or bad? Why?

I think it is good that the aliens are willing to offer all their scientific knowledge to us as their knowledge can be put to good use and better improve our surroundings. Maybe we could invent a rocket or a spaceship just to go to their planet (if they even exist at all). Who knows?

Of course there are advantages of their knowledge. For example, through their knowledge, we can discover more medicine and cures for diseases like cancer. Even with this modern technology, scientists are still unable to cure cancer at the 4th or 5th stage. With that, Singapore would be so advanced that even the other countries with good technology and high speed will be green with envy. The aliens may also be able to provide solutions to our problems with their big brains.

However, every pros has its cons. There are some scientists out there who will get greedy for attention. Due to that, they will invent things that can be harmful to the evnvironment. Say, nuclear rifles. They will abuse the knowledge that they have to create such things just to fulfill their greed. It's not worth it if they are going to end Earth's life like this.

Since there are more advantages, I think that it's good that the aliens are willing to share their knowledge with us, so that we can change for the better, not for the worse.

E-learning assignment Part 1 - Discovery of aspirin.

(http://paddyk.files.wordpress.com/2009/11/5-aspirin.jpg)

I am fascinated by the discovery of aspirin or also known as acetylsalicylic acid. It is a derivative of salicylic acid that is a mild, nonnarcotic analgesic useful in the relief of headache and muscle and joint aches. The person who found invented modern medicine was Hippocrates, who lived between 460 B.C and 377 B.C.

Although aspirin is type of drug, it works by inhibiting the production of prostaglandins which are body chemicals that are necessary for blood clotting and which also sensitise nerve endings to pain. Hippocrates left historical records of pain relief treatments. This includes the use of powder made from the bark and leaves of a willow tree to heal headaches, fevers and many more.

The fascinating aspect is that it is able to relieve fevers and headaches.