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

Stiletto Heels

If you have been going around in a of pair stilettos for the entire day, you most probably would have experienced sore shoulders and some back pain or you would have noticed some growth of thick skin. Stilettos can cause long term damage to one's health and when worn regularly, they can cause harm to our feet and posture. The higher the heel, the worser it will be. Although stilettos can make one taller and have a more attractive posture, the posture is not a natural one and it puts a lot of pressure and stress on the spine when the body is pitched forward. When wearing a stiletto heel, the entire body weight is directed onto the ball of the foot, changing the way you walk. This is because the heel found on your pair of stilettos is extremely long and thin, increasing the amount of pressure put onto your feet, which causes pain after walking in them for a while. Even though wearing flats are a better choice as compared to heels, flats do not offer much support to the arch. 1.5 to 2 inch heels are not just easy to walk in, they also build calve muscles but can cause problems such as corns, calluses and back pain. But if you are wearing 2.5 and above inch heels, you might want to consider leaving them for special occasions or wearing them only a few times a weak. You must always learn to wear different kinds of shoes in a week to minimise foot damage. Remember that whatever height of shoes you choose to wear, it will affect your health. Your feet and back will thank you one day when you are wearing the right kind of shoes.

Picture souce:

http://newsimg.bbc.co.uk/media/images/46563000/jpg/_46563249_heels_ap.jpg

http://3.bp.blogspot.com/_h_O1RXU_SrQ/SdrkyCOm0bI/AAAAAAAAAFg/n6MTTxx5kds/s320/Morgan,+J+stiletto+heels.jpg

http://cache.jalopnik.com/assets/resources/2007/05/Stiletto_Heels.jpg
Source: Watsons Glow singapore October to December 2009 (Magazine)

Ever wondered why there are low and high tides?
This is because at the point directly under the moon, the water is at its closest to the moon. Therefore, there is more gravity which causes tides to rise higher. The water is at its furthest from the moon at the opposite side of the earth so the tides will not rise as high. A tide is a rise and fall of sea levels caused by the combined effects of the moon, the sun and the rotation of the earth. Most coastal areas experience 2 daily low and high tides.
View this video on different types of tides: http://www.youtube.com/watch?v=kHvBUDk7kkQ&feature=related

Cartesian Diver
The 'diver' sinks to the bottom of the bottle when one gently squeezes the sides of the bottle because pressure is applied and compresses the air bubble inside the 'diver' which will increase the density of the 'diver'. When the 'diver' is in the bottle and the bottle is not being squeezed, the air bubble is large enough such that it makes the 'diver' float.

DEAD SEA

The dead sea is one of the world's saltiest water bodies and its salinity does not allow any animals to live there, hence its name. It is 378m deep, 67km long and 18km wide. People use the salt and minerals from the dead sea to make facial or body care products. So why is it possible that we naturally float on the dead sea? There is a high content of salt in the dead sea, therefore, the water is denser. As a result, we are more buoyant in the dead sea so we are able to float and not sink.

Image Source:http://www.deadseanail.com/photos/deadsea2.jpg