Science home learning units research

The interesting unit that I am going to talk about is horsepower. Everytime you see sports cars in newspapers and magazines they would always indicate a "horsepower". It is refering to the power of the car. So, since they are cars, why horsepower and not carpower? Well, that is what I am going to talk about. The word horsepower originally came from the time when steam engines were first invented, replacing the previous horses. People at that time did not know what to compare speed to, and thus compared it to the only form of speed they knew, the horse's speed. They estimated how much power a horse can have and compare it to their new steam engines. The mechanical horsepower of 550 foot-pounds per second is approximately equivalent to 745.7 watts. The unit was not accepted as a SI unit as the definition of the unit varied between geographical regions. Horsepower is useful as the horse is fast, and therefore it is easy to compare with our vehicles now but the disadvantage is that we cannot compare all machineries with the horsepower as even though the horse is fast, our jet planes are far more faster and we therefore cannot compare them. However, it is still useful as it is widely known and can be easily understood by others.

Home learning homework

Question:
Why does the egg float in salt water?
Answer:
Density is equal to mass over volume. The egg is denser than freshwater and floats but when salt was added to the freshwater, the freshwater increased in mass by quite much but not in volume. This results in the density of the now salt water to be greater and the egg. When it is denser, the egg floats.

Use of wrong units in science

The use of wrong units in science can be deadly. An example is the Gimli Glider. It suddenly went out of fuel at 12500m of altitude.Luckily the pilots were skilled and the Glider landed safely. Further investigations have shown that what caused that incident was just a small human error. One part of th team used the new metric system to calculate the amount of fuel given to the Glider while the other used the old imperial system. Such a big mistake was caused by a smal human error--use of different units. Every unit is different,one m cube is equal to 1000000 cm cube. So if you should a plane with 1000m cube of fuel but you calculate it as 1000cm cube, it would have 1000000 times lesser fuel. There are many unit systems in the world, like the imperial units system. However, now the world has adopted a new system widely used, the metric system which has the SI units. M is standard for metres and K is standard for kelvin. Around the world, these units have been used as a base. Imagine one day when you buy your bag of rice it does not say 10kg, but 10 pounds, and you not having heard of pounds before thought it was normal, but you see that the rice bag is smaller and the price is the same. If you only recognise 10, you have been cheated almost half of the bag of rice. However, you will not have any idea what is going on and if you buy the rice twice a month, you will be cheated $5 each time you buy, which is $10 a month and $120 a year. Thus, I conclude that the new units system is to not allow confusion to be made in calculations so that no more such accidents like the Gimli Glider shall occur.

2012

Hi everyone,

Seen the movie 2012?It seems as if it really is happening. More and more disasters are happening these days, the sichuan earthquake not long ago, now the haiti earthquake and if you are aware of the news, there are more and more bushfires, extreme winters and summers occuring these days. Could it have been because of global warming?As you know, when global warming starts, the carbon dioxide rises to outside Earth and forms a large black blanket around Earth. At that time, it will get hotter and hotter on Earth until the light and heat from the Sun is totally blocked out, then the Earth will start getting colder,global cooling, and slowly dies. I read an article about 6 degrees changing the world. If I'm not wrong, by the third degree, Singapore would be underwater. Ahh.....So please start conserving energy to save the Earth, and yourself.