Energy and Much More…
Solar energy makes life possible.
You eat to get energy from food to nourish your body to play and work.
We burn coal, wood or oil to get heat energy to generate electricity to light our houses, streets, offices and factories.
We need energy to DO things.
There are different FORMS of energy: Heat Energy, also called Thermal Energy; Kinetic and Potential Energy; Electric, Chemical, Magnetic and Nuclear Energy.
Photo voltaic panels, catch the solar heat radiation energy and make it into electricity. And the sunflowers catch solar energy as well and make it into food for their growth, flowering and then seeds to grow a new bunch of sunflowers, neat…
You need lots of solar panels to make much electricity, wow a whole field full… Hundreds or thousands?
And here is the science of solar energy and where it goes…
Thermal or Heat Energy: Camp fire, wood stove and a hot shower …
And… Thomas the Steam Locomotive. The coal fire in the firebox heats the water in the boiler and makes steam for the steam engines on both sides of at the front, to drive the wheels and pull the train.
A fireman adds coal to the firebox while the locomotive engineer looks on, a lot of human energy is needed to shovel the coal in, but lots more heat energy is made by burning the coal to heat the water for making steam…
Potential Energy: An avalanche just before it starts to run down a slope, a weight lifted above your head, a rock balanced on top of a ridge, or water at the top of a waterfall…
Kinetic Energy: riding your bike, running, a tennis ball in mid air, diving in a pool , or playing soccer…
Electric Energy: energy made by an electric generator, energy that gives you a shock, the energy that makes light and the energy that heats an electric teakettle…
The man in the photo stands beside a rotor of a steam turbine, a whole bunch of blades like a windmill, but in this case high pressure steam blows against the steel blades and spins the turbine shaft around. The turbine drives a generator and the electrical energy is transported over high voltage lines to your house.
Chemical energy is used in batteries, like the one above, and fertilizer for growing food and to make our muscles work…
So, make sure you eat your breakfast, and a good one, for bio-chemical energy to power you along!
Magnetic Energy: Micro wave oven, magnet picking up steel objects, compass, magnetic levitation train …
And toy magnets.
Nuclear Energy: Nuclear reactor heating water to make steam for turbine to make electricity, nuclear bomb, ultraviolet radiation from the sun …
One form of energy can change into another
When you pedal your bike up a hill, you use chemical energy from a good breakfast to let your muscles do mechanical work to pedal the bike; the bike and you have kinetic energy and you also gain potential energy when you go up the hill.
At the top, you may rest. There is no kinetic energy, but you have lots of potential energy.
Now, coast down the hill at higher and higher speed, you loose potential energy, but you gain kinetic energy! At the bottom, you have to start pedaling again and do mechanical work to keep going.
Conservation of Energy
When energy goes from one form into another, the amount of energy stays the same!
BUT, not all energy is of the same QUALITY.
Energy goes from high quality to low quality and becomes useless after
we have done things with it!
You heat a cup of chocolate milk in the microwave oven, you use electrical and magnetic energy to make it hot. When you leave it on the table, it cools slowly giving off its heat to the air in the room and to the tabletop. It can also move its heat energy to your hands to warm them up after skating or throwing snowballs.
When it is lukewarm or cold, you cannot make it hot again by itself. The electrical and magnetic energy that made the drink hot, has gone to waste as heat energy and it is gone forever
in the very big universe…