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.

Camera

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.

Tape recorder

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, or buildings.

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.

Gadgets:

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 palm sized.

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.

Compiled by Janani Amarasekara