FORMS OF ENERGY - I
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We can find many different forms of energy in nature and we can use them in many different ways. But the most important forms of energy are the mechanical energy, the chemical energy, the thermal energy, the light energy, the electrical energy and the nuclear energy.In this lesson we are going to study the mechanical energy, the thermal energy and the light energy.
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MECHANICAL ENERGY
The mechanical energy is associated with MOVEMENT and DIRECTION CHANGES.
The mechanical energy is associated with MOVEMENT and DIRECTION CHANGES.
- The mechanical energy produces movement when, for example, we push a supermarket trolley.
- The mechanical energy produces a direction change when, for example, we kick a football that is moving.
WE USE THE MECHANICAL ENERGY TO MOVE OBJECTS.
The mechanical energy is the sum of 2 energies: the kinetic and the potential energy.
- The kinetic energy is associated with movement: a tree has little kinetic energy; but a car that is moving has a lot of kinetic energy.
- The potential energy is associated with the position of an object: a bike on a flat road has got little potential energy; but if the bike is at the top of a mountain, that bike will have a lot of potential energy.
What about using a flash animation to see the differences between kinetic and potential energy?
THERMAL ENERGY
Thermal energy (HEAT) is produced by the movement of the particles that make up objects.
All objects are made up of small particles (for example, water is made up of hydrogen and oxygen). These particles are always moving: in some objects they move slowly, but in some objects they move fast.Objects will be hot if their particles are moving fast; and objects will be cold if their particles are moving slowly.
Thermal energy (HEAT) is produced by the movement of the particles that make up objects.
All objects are made up of small particles (for example, water is made up of hydrogen and oxygen). These particles are always moving: in some objects they move slowly, but in some objects they move fast.Objects will be hot if their particles are moving fast; and objects will be cold if their particles are moving slowly.
WE USE THE THERMAL ENERGY TO HEAT UP OBJECTS (SUCH AS BUILDINGS, FOOD,...).
We can change the thermal energy of an object. How? Adding energy to an object: if we add energy to and object its particles will start moving faster, so the thermal energy will increase. For example: if our muscles are cold, we can start jumping (we add mechanical energy) so our muscles will get hotter (the particles that made up our muscles are moving faster now!).
LIGHT ENERGY
This is energy in the form of LIGHT. Many objects can produce light: stars, fire, light bulbs,...
This is energy in the form of LIGHT. Many objects can produce light: stars, fire, light bulbs,...
WE USE THE LIGHT ENERGY TO SEE.
Would you like to learn some interesting facts about light?
- Light is very important as plants need it to perform the photosynthesis.
- Light is very fast: it travels at a speed of about 300.000 km/s. But this speed depends on the object the light is traveling through.
- Light always travels in a straight line.
- Light is always moving, so it can't be stored.
- Light can be decomposed in all the colours of the rainbow.
This lesson is a bit difficult, isn't it? Let's watch some videos to make the explanation easier.
On the first video the Coyote and the Road Runner will explain you the difference between kinetic and potential energy.
On the first video the Coyote and the Road Runner will explain you the difference between kinetic and potential energy.
On the second video you will learn that heat and temperature are different.
On the third video you are going to learn how can we see the different colors in nature.
Would you like to play some games about energy to check what you have learned? Go to the games section.