Pushing
Down
The air above us isn't as heavy as water, but it does put pressure on our bodies. Sometimes our ears even "pop" because of the change in air pressure as we travel in a car or plane.
Since air is a substance, or something that takes up space, we can observe the effect it has on us and the things around us.
The temperature of the air can be measured by a thermometer. If the air is too hot or too cold, it affects our choice of the clothes we wear and the activities we choose to do.
Try it!
Pull a balloon over the mouth of a bottle. Place the bottle in a cold place for ten minutes. How does the balloon look after being in the cold place? Then, place the bottle in a warm place for ten minutes. What happens to the balloon as the bottle becomes warm? Why?
Air moves differently as its temperature changes. Warm
air rises and cool air sinks, creating wind. The chart below was developed
by Sir Francis Beaufort of
Observation |
Estimated
Wind Speed |
| Smoke drifts with air |
1-3 mph |
| Wind can be felt; leaves rustle |
4-7 mph |
| Leaves and small twigs move; flags move |
8-12 mph |
| Small branches sway; dust and paper blow |
13-18 mph |
| Small trees sway |
19-24 mph |
| Large branches sway |
25-31 mph |
| Whole trees sway; walking is difficult |
32-38 mph |
Date |
Time |
Observation |
Estimated Wind Speed |
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| Get the plug-ins: Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information: the title of the activity, the URL (Internet address), and your name. Remember that no pictures can be used which show any student faces or has a student name. Updated
August 18, 2005
by: Glen Westbroek |
