hali the helicopter

the water recycle

The Water Cycle

Run and get a glass of water and put it on the table next to you.  Take a good long look at the water.  Now -- can you guess how old it is?

The water in your glass may have fallen from the sky as rain just last week, but the water itself has been around pretty much as long as the earth has! When the first fish crawled out of the ocean onto the land, your glass of water was part of that ocean.  When the Brontosaurus walked through lakes feeding on  plants, your glass of water was part of those lakes.  When kings and princesses, knights and squires took a drink from their wells, your glass of water was part of those wells. And you thought your parents were OLD

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The earth has a limited amount of water.  That water keeps going around and around and around and around and (well, you get the idea) in what we call the "Water Cycle". This cycle is made up of a few main parts: evaporation (and transpiration) condensation precipitation collection

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Evaporation:   Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air.

Do plants sweat? Well, sort of.... people perspire (sweat) and plants transpire.  Transpiration is the process by which plants lose water out of their leaves.  Transpiration gives evaporation a bit of a hand in getting the water vapor back up into the air.

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Condensation: Water vapor in the air gets cold and changes back into liquid, forming clouds. This is called condensation. You can see the same sort of thing at home... pour a glass of cold water on a hot day and watch what happens.  Water forms on the outside of the glass.  That water didn't somehow leak through the glass!  It actually came from the air.  Water vapor in the warm air, turns back into liquid when it touches the cold glass.

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Precipitation: Precipitation occurs when so much water has condensed that the air cannot hold it anymore.  The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow.

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Collection: When water falls back to earth as precipitation, it may fall back in the oceans, lakes or rivers or it may end up on land.  When it ends up on land, it will either soak into the earth and become part of the “ground water” that plants and animals use to drink or it may run over the soil and collect in the oceans, lakes or rivers where the cycle starts all over again.   source: http://www.kidzone.ws/water/

how was telephone invented?

the law of sir issac newton

newton's law of motion

Newton's laws of motion

Redirected from Newton's second law of motion

The laws of motion (laws of inertia) are the three scientific laws which Isaac Newton described; regarding the motion of bodies. These laws are fundamental to classical mechanics.
Newton first defined these laws in Philosophiae Naturalis Principia Mathematica (1687) and, using his newly developed calculus, proved many results concerning "idealised" particles. In the third volume (of the text), he showed how, combined with his Law of Universal Gravitation, the laws of motion would explain Kepler's laws of planetary motion. Newton's laws were modified, in 1916, by Einstein's theory of relativity.
Newton's First Law (Law of Inertia)

• Every object persists in its state of rest, or uniform motion (in a straight line); unless, it is compelled to change that state, by forces impressed on it.
• A body remains at rest, or moves in a straight line (at a constant velocity), unless acted upon by a net outside force.

This means that a stationary object will remain stationary, and a moving object will continue to move (forever and in the same manner), unless a force acts upon it. In everyday life, the force of friction usually acts upon moving objects. Newton's law indicates that some force (gravity) must be acting upon the planets, as they do not travel in a straight line.
Newton's Second Law

• Force is equal to the change in momentum per change in time.
• The acceleration of an object is proportional[?] to the force acting upon it.

This is expressed by the equation:

• F = ma
  • F = force
  • m = mass
  • a = acceleration.

This expresses that the more force an object receives, the greater its acceleration will be; and that, the less mass an object has, the less force will be needed, to accelerate it; the more mass an object has, the more force will be required, to accelerate it. For example, the force of a nuclear explosion will acclerate a kitten more than a water buffalo; because, the kitten has less mass. This law is associated with the conservation of angular momentum.
Newton's Third Law

• Whenever one body exerts force upon a second body, the second body exerts an equal and opposite force upon the first body.
• For every action, there is an equal and opposite reaction.
• Forces always come in equal pairs.

If you strike an object with a force of 200 N, then the object also strikes you (with a force of 200 N). Not only does a bullet exert force upon a target; but, the target exerts equal force upon the bullet. Not only do planets accelerate toward stars; but, stars acclerate toward planets. The reaction force has the same line of action, and is of the same type and magnitude as the original force.


sources:n http://encyclopedia.kids.net.au/page/ne/Newton%27s_second_law_of_motion

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effects of tsunami

Effects Tsunamis can Make 1. They can destroy lives/drowned loved ones. 2. Wash away properties. 3. Wash away and drowned pets. 4. The sound will make you scared and after it happens you might not be able to sleep well because you might hear the sound of a tsunami at night. 5. You won’t have anything to live like: Food, clothes, shelter, beds and blankets. sources: http://library.thinkquest.org/05aug/01824/tsunamicauses.htm

cause of tsunami

1. A Tsunami is violent disturbance deep below the ocean surface.
2. The under water earthquakes and subduction zones are the most common cause.
How a Tsunami Is Caused
When an oceanic plate hits a continental plate the plates press together and pressure builds.
Eventually the heavier oceanic plate slips under the lighter continental plate and causes an earthquake.
The earthquake lifts part of the ocean up and drops other parts down.
What happens on the ocean floor is mirrored on the surface of the water above.
The gravity acts fast to even out the water’s surface. The seismic energy created that big wave and it doesn’t just disappear. Waves start moving up to 600 miles per hour but you can’t see them.
The Tsunami extends thousands of feet deep into the ocean.
Tsunamis carry lots of water and energy so they can travel very far.

sources: http://library.thinkquest.org/05aug/01824/tsunamicauses.htmces