Wednesday, July 10, 2013

Literature Review (Ibrahim)


What Is Wind
Wind is the air in motion caused by the uneven heating of the Earth’s surface by radiant energy from the sun. Since the Earth’s surface is made of very different types of land and water, it absorbs the sun’s energy at different rates. Water usually does not heat or cool as quickly as land because of its physical properties.
An ideal situation for the formation of local wind is an area where land and water meet. During the day, the air above the land heats up more quickly than the air above water. The warm air over the land expands, becomes less dense and rises.
The heavier, denser, cool air over the water flows in to take its place, creating wind. In the same way, the atmospheric winds that circle the Earth are created because the land near the equator is heated more by the sun than land near the North and South Poles. Today, people use wind energy to make electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines.
It is important in many cases to know how fast the wind is blowing. Wind speed can be measured using a wind gauge or anemometer. An anemometer is a device with three arms that spin on top of a shaft. Each arm has a cup on its end. The cups catch the wind and spin the shaft. The harder the wind blows, the faster the shaft spins. A device inside counts the number of rotations per minute and converts that figure into miles per hour. A display on the anemometer shows the speed of the wind.

Wind Chill Factor
When the wind blows across the exposed surface of our skin, it draws heat away from our bodies. When the wind picks up speed, it draws more heat away, so if your skin is exposed to the wind, your body will cool more quickly than it would have on a still day.

The actual formula for wind chill. Just in case you ever find yourself with a calculator, thermometer, and anemometer but without access to The Weather Channel, the Fahrenheit version of the equation looks like this:
Wind Chill = 35.74 + 0.6215T "“ 35.75(V^0.16) + 0.4275T(V^0.16)
T is the air temperature in degrees Fahrenheit, and V is the wind speed in miles per hour.
Bibliography
Ethan Trex. (December 27, 2010). Mental Floss. In How Is Wind Chill Calculated?. Retrieved July 10, 2013, from http://mentalfloss.com/article/26730/how-wind-chill-calculated
need.org (2012). National Energy Education. In Wind Energy. Retrieved July 10, 2013, from http://www.need.org/needpdf/infobook_activities/IntInfo/WindI.pdf

Literature Review (Wun Juan)

Project Title: An investigation on how wind speed affect how quickly an object cools

Wind

Wind is simply air in motion. It is caused by the uneven heating of the Earth’s surface by radiant energy from the sun. Earth’s surface is made of very different types of land and water, so it absorbs the sun’s energy at different rates. Water usually does not heat or cool as quickly as land because of its physical properties. An ideal situation for the formation of local wind is an area where land and water meet. During the day, the air above the land heats up more quickly than the air above water. The warm air over the land expands, becomes less dense and rises. The heavier, denser, cool air over the water flows in to take its place, creating wind. In the same way, the atmospheric winds that circle the Earth are created because the land near the equator is heated more by the sun than land near the North and South Poles.

Wind Speed

Wind speed can be measured using a anemometer. One type of anemometer is a device with three arms that spin on top of a shaft. Each arm has a cup on its end. The cups catch the wind and spin the shaft. The harder the wind blows, the faster the shaft spins. A device inside counts the number of rotations per minute and converts that figure into miles per hour. A display on the anemometer shows the speed of the wind.

Wind Chill Factor

A phenomenon called the Wind Chill factor makes us feel colder in winter than the air temperature really is. This is due to the interaction of air temperature and wind on the human body that is already giving off heat. Both temperature and wind cause heat loss from body surfaces. A combination of cold and wind makes a body feel colder than the actual temperature.
References: 

Wind Energy, (2012). Retrieved July 10, 2013, from http://www.need.org/needpdf/infobook_activities/IntInfo/WindI.pdf


James P. Dildine, Brrrr....Wind Chill is Chilly (1999). Retrieved July 10, 2013, from http://mste.illinois.edu/dildine/wind_chill/#contact

Chosen Project Title

Our chosen project title: An investigation on how wind speed affect how quickly an object cools.

Monday, July 8, 2013

Literature Review (Shaquille's)


The Wind Chill Factor
Basically, wind chill is the temperature which us, humans would feel, although it is not what we think. For example, in a cold country, the temperature could read 0C, but as wind blows, it will actually feel like -6C. That is wind chill. Why does this happen? To start, the human body has a core temperature of roughly 37C, while the temperature of the surrounding air is usually below 37C (assuming in a cold country). So, if a breeze blows, it cools the temperature of our skin to almost air temperature. 

Although wind chill affects us humans, it does not actually work the same way on inanimate objects, like water, for example. Lower wind chills mean that inanimate objects cool to the air temperature more quickly, but even high winds can't force the object's temperature below the air temperature. What is meant by that is, wind chill is not able to lower the temperature of an object, below the air temperature. For example, even when your skin feels like 0C, but the surrounding air temperature is only 6C, the water is not able to freeze even though it feels like it is at its freezing point. 

To measure wind chill, there are a few things that are needed to be justified. They are; wind speed and the temperature of the surrounding air. The measurement of wind speed is usually done with an Anemometer, while the measurement of the surrounding air is simpler, with a Thermometer. 

Bibliograpy

Ethan Trex. (December 27, 2010). Mental Floss. In How Is Wind Chill Calculated?. Retrieved July 10, 2013, from http://mentalfloss.com/article/26730/how-wind-chill-calculated

Chan Sai-tick. (March 2011). Hong Kong Observatory. The Wind Chill Effect. Retrieved July 10, 2013, from http://www.hko.gov.hk/education/edu01met/wxphe/ele_windchill_e.htm

Wednesday, July 3, 2013

Hypothesis for each project title

1. An investigation on how wind speed affect how quickly an object cools.

Hypothesis: The higher the wind speed, the quicker the object cools 

2. An investigation of the Greenhouse Effect.


Hypothesis: The more Co2 present in the air, the warmer the surrounding temperature will be.

3. An investigation on the effects of fertilisers on algal growth.

Hypothesis: If the concentration of fertiliser is higher, the faster the growth of algae. 

Tables for each project title