Fremont Magnet Elementary

• The Sun is made of helium and hydrogen.
• The Sun is the largest thing in our solar system.
• The 9 planets orbit the Sun because of the gravitational attraction between them.  

Quick Check -

Which of these is true about the Sun

The Sun ____

  is a star and is not in the center of the solar system
  is not a star and is in the center of the solar system
  is a star and is in the center of the solar system

Which of these revolves around a planet?

  an asteroid
  a moon
  a star

2. What is Air Pressure?

Air pressure is the force put on you by the weight of air molecules. You know that air molecules are invisible, but they still have weight and take up space.

The air molecules are pushing against your body right now.  Do you think the force (how hard they are pressing) is

  greater pressing down on the top of your head
  greater pressing on the sides of your body
  equal in all directions

3. What is the Atmosphere?

The atmosphere is the air that surrounds the Earth.  We live at the bottom of a 'sea of air'.  The higher you go in the atmosphere, the less air molecules there are in the 'sea of air'.

If there are less air molecules, does that mean the air pressure increases or decreases as you go higher?

  increases (more)
  decreases (less)

4. Why don't I feel the pressure?

The reason you don't get squished by the pressure of the atmosphere is because you have air inside your body.  The air inside your body is the same as the pressure on the outside.

When you drive up the mountains to Los Angeles, what happens to your ears? 

Your ears pop because the air pressure is different as you go higher through the mountains.  When the air inside your body changes so that it will be the same as the new pressure outside your body, your ears pop.

Is the pressure in the mountains higher or lower than here in the valley?

higher
lower

5. Try It!

A balloon filled with air can't release the air inside as it goes higher, like we can.  What do you think would happen to a balloon as it rises higher and higher in the air?

Remember - the air outside the balloon will have less pressure as it get higher.

Click here to find out by moving your mouse over the altitude scale.

Now you know that the higher you go, there is less air and less air pressure, but did you know... the air gets colder too? 

Draw a picture or write about what you have learned.

It's a Breeze - How air pressure effects you

http://www.eduplace.com/science/dw/5/ca/ift/e/index.html

BrainPop Atmosphere