Levers

Levers are basic tools probably used since prehistoric times. They were first described by Archimedes. A lever is a simple machine which makes work easier, which involves moving a load around the pivot or fulcrum using an effort.
Watch this video on levers:
http://www.youtube.com/watch?v=wV1pYkTtsxg


In a first class lever, the fulcrum/pivot is in the center of the load and effort. Some examples are the see-saw, scissors and pliers.

In a second class lever, the load is in the middle of the fulcrum/pivot and the effort. Some examples are staplers, wheelbarrows and nail clippers.

In a third class lever, the effort is between the load and the fulcrum/pivot. Some examples are fishing rods, thongs and tweezers.

Sources:

http://www.enchantedlearning.com/
http://www.pbs.org/wgbh/nova/teachers/activities/images/27ms_sle2treb_levers.gif

http://www.istockphoto.com/file_thumbview_approve/6952789/2/istockphoto_6952789-fishing-bear.jpg
http://www.sciencefairprojects-ideas.com/images/stories/seesaw.jpg

Conservation of energy

It is always important to conserve energy because most of the energy we use comes from non-renewable sources, like fossil fuels. They are limited and will run out one day. Some scientists estimated that they will all be used up by the next 200 years. Therefore, it is a must for everyone to conserve energy. The law of conservation of energy states that energy can change from one form to another but it cannot be destroyed or created.

What is Biomass?

Biomass refers to plant and animal material from which oil can be extracted, fermented into gas or burned. Oil palm, jatropha or jojoba are examples of which oil can be extracted to be used for lighting, heating and cosmetics. They can also be turned into biodiesel fuel for vehicles.
A video on Biomass: http://www.youtube.com/watch?v=79nW2o-kYa4
Picture Sources: http://www.infocoreonline.net/computerjunction.in/be1.jpg

Energy

Renewable energy is an energy that comes from natural sources that naturally replenishes, such as, sunlight(solar power), wind(wind farms, wind turbines), rain, tides and geothermal heat(heat stored in the Earth). Non-renewable energy is a natural source that cannot be re-grown, produced or generated and they are used up faster than the Earth can recreate them. It includes fossil fuels like coal, oil and natural gases which will be used up one day so the future generations will not have any of these sources left.

Source: http://www.sonic.net/~lilith/EnviraFuels/images/renewable-vs-non.gif

Biomass

Source: www.google.com

What I have learnt as a summary...
Through the airplane videos, I have learnt about the conservation of energy and why certain airplanes fail in mid-air. Some reasons could be fuel leaks, mistakes by the pilot, bad weather and many other causes.

Formula for...
Density: Mass/Volume
Pressure: Force/Area
Work done: Force(Newtons) x Distance(Metres)= Work done(Joules)
~1ooo Joules= 1kilojoule
~1000 kilojoules= 1 megajoule
~1 kilogram= 10 Newtons
~1 Newton metre= 1 Joule