Heat Energy
This topic is all about energy and how we can save energy. Firstly we need to find out what energy actually is. There are lots of different ideas that people have.
BUT SO WHAT????
Well, energy on our plant Earth is running out because we use so much of it. It is expensive, so we need to learn about energy so we can use it wisely. We need to save energy and we need to come up with new ways of "harvesting" energy.
Watch this clip about the future of energy use:
Watch this clip about the future of energy use:
It can be quite hard to measure energy so we usually do this by measuring the changes that energy causes. This is called doing WORK (W). This is the term used scientifically in Physics. Sometimes it is called Work Done (WD)
Energy is measured using units called Joules (J). An old unit of measurement is calories (cal). Joules are quite small units so you will often see kJ as a measure meaning kilojoules.
All the packaged foods you eat have a calorie of kJ rating to tell you how much energy they have in them. It tells you haw much chemical energy is in the food.
Energy Laws
Scientists have discovered so important ideas about Energy. They are so important they are called the Energy Laws. You will need to remember the first law, but more importantly you will need to understand the meaning. As you do your investigations you should be thinking about how these laws fit into your findings.
First Law of Energy: Energy Conservation Law
Energy can never be created or destroyed This means that you can’t make energy out of nothing— the total amount of energy in the universe is a constant. (Please note that this applies to a closed system – the Earth is not a closed system, the Earth receives energy all the time from the Sun).
It is called conservation because to conserve means to "save".
It is called conservation because to conserve means to "save".
Energy is sometimes called "Lost". This means that we cant access it or use it... it is actually wasted energy, not really lost. We do know where it is gone. It has usually been changed to a form of energy we cant use such as heat or sound.
One of the challenges of today's world is to try and get this wasted energy and reduce or wasted energy. That is the whole idea about energy conservation.
One of the challenges of today's world is to try and get this wasted energy and reduce or wasted energy. That is the whole idea about energy conservation.
Main forms of Energy: Kinetic and Potential Energy
Kinetic energy is "active" energy... it is happening now. This is energy in action.
Potential energy is "stored" energy. Nothing is happening. Something could happen later.
Potential energy is "stored" energy. Nothing is happening. Something could happen later.
Energy Changes/Energy Transformation
KINDS OF ENERGY
Transfer of Heat
Convection currents
Basically hot things go up and cold things go down
In other words HOT AIR RISES
In other words HOT AIR RISES
An 8 min clip about Heat transfer... especially selected for you!!! The second clip is about heat transfer in houses.
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Below is a link to a "Teded Talk" explaining energy concepts