McGraw-Hill Science 2005

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Macmillan/McGraw-Hill Science Grade 3
Grade 3
e-Journal

Gravity

Step 1. Questions

Jump up into the air. Very quickly, you fall back down to Earth. Why? Earth’s gravity pulls on you and everything around you.

Gravity is an invisible force. You cannot see it, but it’s there. Earth’s gravity even extends to the Moon! The Moon stays in its orbit because Earth’s gravity holds it there.

For this e-Journal project, you will research and report on gravity. Here are some questions to guide your research.
  • What does gravity do?
  • Do two small things, like a pair of ping-pong balls, pull on each other because of gravity? If yes, why don’t we see the effects?
  • Along with gravity, what force keeps Earth’s Moon in its orbit?
  • Why is the Moon’s gravity less than Earth’s gravity?
  • What would the Universe be like without gravity?
  • What questions do you have about gravity?
Are you ready? Begin by visiting the three Web sites listed in Step 2. You may also use search engines to research more about gravity or its role in the Universe. Or find books at the library.

Take notes in the note-taking boxes. When you are ready, follow Steps 3 and 4 to write your report.


Step 2. Research

Research answers for the questions you were asked in Step 1. Visit these Web sites. Take notes about them on this page, too!

Our Place in Space: Gravity
The wonderful “Ology” Web site presents this fun page on Gravity. Click the cartoon images to learn what gravity does and how it works.
Take Notes:



Gravity Definition Page
What is gravity? Read the definition on this page. Then explore other parts of the site to learn about gravity in the solar system. This page is part of the Windows to the Universe Web site.
Take Notes:



What Goes Up Must Come Down
This Web page begins with an old saying about gravity. Read the story of Isaac Newton and gravity. Keep clicking “Next” for more gravity information.
Take Notes:



Additional Sites

Funderstanding Roller Coaster
Have fun as you learn to understand the “Funderstanding” roller coaster. Click on the dials to change the shapes of the hills and the loop. Or make gravity stronger or weaker. Click the arrow to launch the coaster, then watch its path. (NOTE: This site may take a minute or so to load onto your computer.)
Take Notes:



Go to Step 3 or Save My Notes


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