How work is related to energy
Have you seen on television or films bullet trains racing down the
track at a very high speed? When the train moves fast over a long
distance, the train is doing a lot of work.
The train moves because it has energy, or the ability to do work.
Anything that has energy can do work. We humans get energy to do work
from food. So, from where does the bullet train get its energy to do its
work? From electricity. If electricity runs out or is shut off, no
energy will be left for the train to move.
The train will not be able to do any work and stop on its tracks.
Cars and other vehicles generally get their energy from fuel. Examples
of work and energy are all around us. At this very moment when you are
reading this article, you are using some sort of energy to do so.
Even though you may be sitting still, your heart is pumping blood
throughout your body. If you place your hand on your chest, you will
feel your heart beating because it's working. Your heart will do this
work as long as you live.
As we mentioned earlier, the energy for our bodies to do work comes
from the food we eat. You do not need a lot of food and energy just to
keep your heart pumping. But, the more work you do, the more energy you
will need. Running is a lot of work. That is why the athletes eat
balanced meals so they will have enough energy to practise and
participate in events.
The moving sail ship is another example of work and energy. Energy
from the wind enables the ship to move through the water. The wind's
energy also moves dust, fallen leaves, and kites.
When you push an object, it moves because it has energy. When the
object runs out of energy, you gave it, it will stop moving. Why does
this happen? Because the object does not make the energy it needs to
move. However, the object does not destroy energy when it stops. Energy
cannot be made or destroyed.
It can only change form or move to another place. You give the object
energy when you push it with your finger. If the object hits another
object, the energy you gave it quickly passes to the other object.
Dominos are a good example of energy passing from one object to another.
When you push the first object the rest continues to fall until the
energy reaches the last object.
When the energy passes through the object it can turn into various
other forms of energy like heat and sound.
Useful tips when collecting data
When you are doing an experiment you need to collect data. Today we
will give you some facts about how to use a camera, tape recorder, map
and a compass to collect data.
You can use a camera to record what you observe in nature. When
taking photographs keep these tips in mind.
1. Hold the camera steady. Gently press the shutter button so that
you do not jerk the camera.
2. Try to take pictures with the sun at your back. Then your pictures
will be bright and clear.
3. Don't get too close to the subject. Without a special lens, the
picture could turn out blurry.
4. Be patient especially when taking nature photographs. If you are
taking a picture of an animal, you may have to wait for the animal to
appear for a long, long time.
You can record observations on a tape recorder. This is sometimes
better than writing notes because, with a tape recorder, you can record
your observations at the exact time you are making them.
Later you can listen to the tape and write down your observations.
This method would prove more beneficial because you do not need to take
your eyes off what you are observing, even for a second, to make notes.
Use a map and a compass
When you are busy observing nature, you might easily get lost. You
could get carried away while following an animal and wander too far.
Remember to carry a map of the area and a compass to find your way in
case you get lost. Here are some tips.
1. Lightly mark on the map your starting place.
2. Always know where you are on the map compared to your starting
place. Watch for landmarks on the map, such as a river, a pond, trails,
3. Use the map and compass to find special places to observe, such as
a pond. Look at the map to see what direction the place is from you.
Hold the compass to see where that direction is.
Speakers for computers
The numerous designs and functions of the speakers catch our
imagination nowadays. The latest innovations open new possibilities.
There are so many types that you do not even know what to choose from.
Let us try to investigate some of the speaker types available today.
First, let us enlighten you about the Digital USB apple-shape
speaker. This little speaker is perfect for a laptop. The gadget does
not take much space, looks stylish and is unusual. There is absolutely
nothing complicating with the installation. Everyone will appreciate
your taste and your choice.
Then, let us see the next type - Bear speaker. This gadget is much
more than a usual speaker. The funny design will decorate the general
look of your computer. Furthermore, the speaker has a unique function -
this little bear combines the function of speaker and radio. Therefore,
you do not need any other gadgets or programmes to listen to your
favourite radio station.
Speaking about the size of the speaker, a majority of people prefer
to have the smallest speaker. For such people, the Super Mini Sound Box
is ideal. It has two important advantages. The first one is that it is
It is so compact that you can use it anywhere and there will be
always a little place for it on your working table. The second advantage
is that it can be connected to all iPods, MP3, MP4, MD, CD player,
notebook, PC, PDA, PSP, and even your mobile phone. It is very handy. In
spite of the size, the gadget plays the role of a nice speaker.
Well, we hope you will be able to decide on the best speaker without
getting lost in this diversity of colours, features and designs
available in the market today.