Monday, April 1, 2013

Weather



Check weather forecast of the Maldives!



Is it same as your observations?
Now check today's weather!
http://www.meteorology.gov.mv/met/

For more information about the weather elements:
http://www.scalloway.org.uk/weat1.htm

All about weather. Please read this!
http://www.oocities.org/sg/c_pling/weather.html

Quiz : Weather and Climate

Upon completion of this quiz you should be able to understand the basic differences between weather and climate and the major controls over them, as well as the role of the Coriolis effect in atmospheric circulation. http://wps.prenhall.com/esm_mcknight_physgeo_9/84/21603/5530553.cw/content/index.html

Saturday, March 2, 2013

Water cycle

Introduction

 Check out this video to see how water cycle works.

 

 

Like all matter, water is constantly cycled through ecosystems. This compound comprises nearly 70 percent of our bodies and is used in many of our chemical reactions. The oceans contain about 97 percent of the world's water. The remainder is fresh water that is in the form of gas (vapor), liquid, or ice. Seventy five percent of this water is frozen in glaciers and in ice in the polar regions. Only about 1 percent of the earth's water is available as fresh, liquid water.
Much of this fresh, liquid water is found in the ground in rock and soil layers. The zone in the earth that contains water saturated soil and/or rocks is known as an aquifer. The upper surface of an aquifer is known as the water table. The remainder of our fresh water is found in the surface water of lakes, rivers, and ponds, and in the bodies of organisms.

The Components of the Water Cycle


  1. The movement of water into the atmosphere--molecules of water, like molecules of all liquids, are in constant motion.
  2. Because of this, what happens to these molecules? They collide with each other, causing them to move to a less crowded area.
  3. What is the movement of particles from a crowded to a less crowded area called? Diffusion. When water diffuses from the soil or from a body of water, it changes from a liquid to a gas form.
  4. What is this diffusion of water called? Evaporation. Water is also released from the bodies of organisms and evaporates into the atmosphere.
  5. In what ways do animals release water? Excretion, exhaling, and perspiration
  6. Where is water released from plants? Mostly from microscopic pores in their leaves
  7. What is transpiration? The evaporation of water from pores of plants

The Formation of Clouds

  1. As water diffuses into the atmosphere, it will become cooler. Also, the air molecules and tiny dirt particles it mixes with will become increasingly farther apart. (The air pressure decreases.) The presence of
  • water molecules
  • dirt particles, also known as condensation particles
  • a decrease in air pressure
  • a decrease in air temperature result in condensation
  1. What is condensation? Process whereby water changes from a gas to a liquid. As they condense, the water molecules attach themselves to nearby condensation (dirt) particles. The result is a cloud droplet. Many, many of these droplets form a cloud.

Precipitation

  1. Eventually the clouds become heavy with water.
  2. What is precipitation? Water in clouds falling to the earth as rain, snow, sleet, or hail.
  3. Explain what becomes of the precipitation? It may seep into the soil and become part of the ground water (aquifer). Much of the water enters the roots of plants. Some enters into the cells of microscopic organisms, and some enters the bodies of animals when they drink water or when they eat other animals. Some of the water moves along the surface in rivers and streams.
  4. What is this water flow along the surface called? Runoff
  5. What becomes of this water? It enters various bodies of water.
  6. If water is constantly cycled, why do we need to conserve water? The water we fail to conserve will. over time. pass through the cycle and return to the earth in some form of precipitation, but it may return many. many miles away. Also, water pollution is still a problem: therefore, it is wise to conserve water that is safe to drink. This completes the water cycle.

Exploring the Components of the Water Cycl

( Carry out these experiments at home)
Experiment 1: Transpiration
Materials
  • small potted plant
  • clear plastic bag
  • twist tie
  1. Put a plastic bag over a small potted plant or over one of its branches and secure the base of it with a twist tie around the stem. For quicker results, put the plant in a warm, preferably sunny location and observe throughout the period.
  2. Explain what you observed on the inside of the plastic bag. Water from the plant diffused into the air and collected on the inside of the bag.
  3. What is the process of water diffusion from plants called? Transpiration
Experiment 2: Cloud Formation Part 1
Materials
  • flask
  • stopper (one holed) for top of flask into which the syringe fits
  • water
  • matches
  • large plastic syringe
  1. Place enough slightly lukewarm water in the bottom of a flask to cover the bottom. Fit the top with a one holed stopper into which a large plastic syringe has been inserted vertically. Remove the stopper/syringe assembly. Light a match. Hold it over the mouth of the flask and blow it out so that some of the smoke if forced down into the flask. Quickly replace the stopper/syringe assembly and while holding it down, pull up on the plunger in the syringe. Observe the inside of the flask.
  2. Explain the change that you observed inside the flask. Pulling up on the plunger decreased the air pressure inside the flask causing the water molecules to condense onto the smoke particles (condensation particles). A cloud formed. (Note: Pushing the plunger back down increases the air pressure. The water molecules move away from the smoke particles. The cloud "disappears.")
  3. What three conditions were present in this experiment that enabled a cloud to form? Condensation particles, water, and a drop in air pressure
  4. What condition that is often involved in cloud formation is not involved in this experiment? A decrease in temperature
Experiment 3: Cloud Formation Part 2
Materials
  • 400-500 ml beaker or jar
  • plastic wrap
  • water
  • rubber band
  • matches
  • ice cubes
  1. Fill a 400-500ml. beaker fill with lukewarm water. Light a match and hold it over the beaker. Then blow it out forcing some of the smoke down into the beaker. Quickly put a piece of plastic wrap over the beaker and secure it if necessary to keep in the smoke. Observe the beaker for any change in the air above the water. After 30 seconds, place 2-3 ice cubes on top of the plastic. Observe again.
  2. Why was there very little, if any, change in the air before the ice cubes were placed over the top? Not enough conditions were present for cloud formation to occur.
  3. What conditions for cloud formation were present before the ice was added? Water and smoke particles
  4. Explain the change you observed after the ice was added. The temperature of the air dropped enabling the water to condense onto the smoke particles forming cloud droplets and therefore, a cloud.
  5. What condition that is often involved in cloud formation was not present in this experiment? A drop in air pressure.
  6. When you see fog, what are you actually seeing and what caused it to form? It is a cloud over the earth's surface due to a sufficient amount of water molecules and dirt particles in the air. along with a drop in air pressure and/or a drop in temperature.


 Reff ;  http://ecosystems.psu.edu/youth/sftrc/lesson-plans/water/6-8/watercycle

Monday, February 18, 2013

Friday, February 8, 2013

Calculation of time





The International Date Line

The International Date Line (IDL) is an imaginary line of longitude on the Earth’s surface located at about 180 degrees east (or west) of the Greenwich Meridian.
The date line is shown as an uneven black vertical line in the Time Zone Map above and marks the divide where the date changes by one day. It makes some deviations from the 180-degree meridian to avoid dividing countries in two, especially in the Polynesia region.
The time difference between either side of the International Date Line is not always exactly 24 hours because of local time zone variations.


Read the information given in the power point to know more about the time.
http://www.wisc-online.com/objects/ViewObject.aspx?ID=SOC3702


Here is current location time in Maldives.
http://www.timeanddate.com/worldclock/city.html?n=715

Saturday, February 2, 2013

Phases of the moon



Understanding The Moon Phases
Have you ever wondered what causes the moon phases? We all know that its appearance changes over time. But why? The good way to understand the phases of the moon is to examine an earth-moon-sun diagram:








Moon Phases Simplified

It's probably easiest to understand the moon cycle in this order: new moon and full moon, first quarter and third quarter, and the phases in between.
 new moon occurs when the moon is positioned between the earth and sun. The three objects are in approximate alignment (why "approximate" is explained below). The entire illuminated portion of the moon is on the back side of the moon, the half that we cannot see.

At a full moon, the earth, moon, and sun are in approximate alignment, just as the new moon, but the moon is on the opposite side of the earth, so the entire sunlit part of the moon is facing us. The shadowed portion is entirely hidden from view.

The first quarter and third quarter moons (both often called a "half moon"), happen when the moon is at a 90 degree angle with respect to the earth and sun. So we are seeing exactly half of the moon illuminated and half in shadow.


After the new moon, the sunlit portion is increasing, but less than half, so it is waxing crescent. After the first quarter, the sunlit portion is still increasing, but now it is more than half, so it is waxing gibbous. After the full moon (maximum illumination), the light continually decreases. So the waning gibbous phase occurs next. Following the third quarter is the waning crescent, which wanes until the light is completely gone -- a new moon.

( Ref: http://www.moonconnection.com/moon_phases.phtml)

 
Activity:
1: See this link for a better understanding of the phases of the moon
http://www.science-class.net/PowerPoints/Moon_phases_files/frame.htm 


2: Lunar Cycle: complete the calendar by filling them with the correct moon phases for all days.
http://sciencenetlinks.com/media/filer/2011/10/14/moon_challenge.html  


3: Self check quiz:
http://glencoe.mcgraw-hill.com/sites/0078617006/student_view0/unit7/chapter23/section_2_self-check_quiz-eng_.html 

Eclipses

What is eclipse? and what causes eclipse?

     







Read this  

http://www.publish.csiro.au/multimedia/projects/eclipses/index.htm 

Further reading: http://www.mreclipse.com/Special/SEprimer.html

Once you finished reading do the following activity.

Activity
Quiz 1:
http://www.astronomyquiz.info/lunar-eclipses-quiz.html

Quiz 2:
http://www.astronomyquiz.info/solar-eclipses-quiz.html



Monday, January 28, 2013

Seasons



Seasons occur because of Earth's changing distance from the Sun





Earth experiences seasons because our planet tilts 23.5° with respect to its orbital plane. During summer Earth's North Pole tilts toward the Sun.
At the same time, however, the South Pole tilts away from the Sun. That means winter is at the southern hemisphere, and summer at the northern hemisphere.


And, regarding distances, Earth is approximately 3 million miles (5 million km) closer to the Sun in early January than it is in early July. That works out to a bit more than a 3 percent swing from Earth's nearest approach to the Sun to its farthest. Although small, 3 percent is not insignificant. The different distances mean the Southern Hemisphere receives more solar energy during its summer than the Northern Hemisphere does in its summer.




Summer and winter occur on dates called the solstices, which mark the highest and lowest points the Sun reaches in our sky. In the Northern Hemisphere, the Sun stands 47° (our planet's 23.5° tilt times two) higher in the sky June 21 than it does December 21. So, around June 21 of each year, summer begins north of the equator, and winter begins south of that line. For this reason, it's incorrect to call June 21 the "summer" solstice. Summer begins on that date only in the Northern Hemisphere. Here at the magazine, we use the terms June solstice and December solstice to signify these dates.

Activity:Match the questions and the answers!

Exercise 1: Quiz

http://www.neok12.com/quiz/SEASON01

Exercise 2: Quiz

http://www.neok12.com/quiz/SEASON02

Exercise 3: Lable the diagram

http://www.neok12.com/diagram/Seasons-01.htm


Exercise 4: Vocabulary practice


http://www.neok12.com/vocabulary/Seasons-01.htm




Were you able to complete all the exercises?
 Do not worry even if you cannot get the correct answer from the first try.
The more you practice the better you become!

Wednesday, January 23, 2013

Movements of the Earth

Movements of the Earth :  Revolution and Rotation of the Earth



The earth revolves around the sun. Besides this it also rotates on its own axis. Thus the earth has two motions, the rotation and the revolution.
Rotation
The earth rotates on its axis from west to east. The axis is an imaginary line passing through the northern and the southern poles of the earth. The rotation of the earth is completed in about 24 hours and it is called the daily motion of the earth. This motion is responsible for the occurrence of day and night.
As a result of the apparent motion of the sun, the appearance of the night sky as seen from the earth changes from day to day. 
Revolution
The movement of the earth around the sun in its orbit is called revolution. This movement of the earth is also from west to east. The period of revolution is one year (365 1/4 days). The orbit of the earth around the sun is elliptical and not circular. 

An interactive animation demonstrating the rotation of the Earth and how day and night arise. Two views are shown, illustrating how a point on the Earth experiences day and night, with the time and sunrise and sunset indicated.

ACTIVITY

Click the following link to see the animation of the moving earth. 

Remember to take the quiz!