What Is Energy?
To answer the question “what is energy?” It is necessary to point out first, energy is any thing that happens and it is defined as the capacity to do work.
What Are the Forms of Energy?
Energy has many forms
- light energy
- heat energy
- electrical energy
- kinetic energy
- sound energy
- potential energy
- chemical energy.
Light energy from the sun to make plants grow. Light produces a photographic film to help us see.
Heat energy is another kind of energy. Heat from the sun produces our weather. It also runs cars through combustion, cooks food, and warms our home in cool seasons.
Electrical energy is yet another type of energy. It produces light and runs motors, computers, televisions, washing machines and many more appliances around the home.
Kinetic energy or movement energy can be seen by the wind which powers sailing boats that cause them to move, or turn windmills. Moving water that turns turbines to produce electricity is a form of kinetic energy.
Sound energy is caused by vibrations which move through the air. Suppose some sounds are made… the sound wave make your ears drum vibrate and in turn it makes the 3 tiny bones to vibrate. If you were place in a vacuum you would not be able to hear the sound.
Potential energy is commonly known as stored energy – for example a stretch rubber band has potential energy because when released it will move. The potential energy in the rubber band case has changed from stored energy or potential to movement energy or kinetic when released.
Chemical energy is stored in food and it is this energy that helps you grow, or helps repair skin cells if you cut yourself. Chemical energy is found in fossil fuels for example when used to produce electricity changes many times
Solar energychemical heat kinetic electrical
What else do I need to know about energy?
The Law of Conservation of Energy states the total amount of energy is fixed – in other words it cannot be created or destroyed
What Is Power?
Power is the rate at which energy is used. Power is measured in Joules per second or watts as in light globes. A 100 watts light globe uses 100 joules of energy per second or a 60 watt globe use 60 joules of energy/second.
The electricity meter in your home measure electricity energy in kilowatts per hour – one kilowatt is 1000 watts used for one hour. A power station is measured in megawatts where one megawatt is 1 million watts.