Science is the explanation of whatever is happening around us in a logical way. There are certain things in nature, the mechanism of which we know by heart and those simple mechanisms lay the foundation for greater happenings. Initially when man was ignorant he did not know about these simple things that happen around us like why and how it rains and why certain metals attract some other metals. Early man also wondered why plants move towards sunlight and the cause behind lightening and thunder but now modern man knows it and we have got to pass on this basic knowledge to the next generation. Only when they understand the basics they would comprehend the greater phenomena of nature. They would admire and try to explore it instead of being in awe of it.
- Experiment 1 - Swinging cereal
A plastic comb, small pieces of dry cereal (O-shapes, or puffed rice of wheat), thread.
Tie a grain of the cereal to one end of the thread. Attach the other end of the thread to something so that the cereal does not hang close to anything else, it can be tied to a pencil or it can be stuck or glued to one of the edges of the table. Take a comb and wash it to remove any oils and dry it well. Once the comb is run through long, dry hair several times, or briskly rubbed against a wool sweater, it would be charged. It can be understood since when the comb is brought near the cereal the cereal swings to touch the comb. It has to be held until the cereal jumps away by itself. Now try and touch the comb to the cereal again. This time it will move away as the comb comes near. Taking a balloon instead of the comb can also help in this experiment.
When the hair was combed the electrons moved from hair to the comb. The comb already possessed of a negative static charge. The cereal that was neutral was therefore attracted to it. When the cereal and the comb touched, the electrons slowly got transferred from the comb to the cereal. Now both objects having the same negative charge repelled each other.
- Experiment 2 - Poles of a Magnet
Magnet, a string, tape
A magnetic rod can be used as a compass, but the first thing that has to be done is to find and mark the North Pole on it. Now a long string can be tied by passing it through the hole in the handle of the rod, and turn towards north. Now the rod should be allowed to hang freely on the string so that it can move in any direction. It should be remembered that on the magnet the poles are on the flat sides of the magnet. So now when the rod stops whirling, that side of the magnet that faces north should be marked with a piece of tape. This side is the north- seeking pole of the magnet.
The earth is also like a big piece of magnet and it also has its North Pole and South Pole. The magnetic North and South Poles are also located near the geographic North and South poles, which are located opposite to each other. However the magnetic poles keep moving from one place to another each year. Therefore to determine the magnetic south and north poles a magnetic wand or compass is required which always points towards the magnetic north.