Plants need several things to live. They take water from the ground through their roots. They also take a gas called carbon dioxide from the air. Plants use sunlight to turn water and carbon dioxide into glucose.
http://www.freesciencefairproject.com/projects/why_leaves_change_color.html
The apparatus consists of a heavy object that is dragged steadily with an elastic cord. Although pulled with a constant velocity, the heavy object repeatedly slides and then stops.
http://pubs.usgs.gov/of/1998/ofr-98-0767/
To measure the amount of water stored in the pore space of a soil sample.
http://www.spacegrant.hawaii.edu/class_acts/Porosity2.html
The purpose of these activities is to increase students awareness to the point where they can make intelligent decisions on proper land use.
http://www.col-ed.org/cur/sci/sci03.txt
A fan disperses the tephra downwind where it accumulates to form a cinder cone.
http://volcano.und.nodak.edu/vwdocs/volc_models/explosive.html
It's easy to simulate the formation of radiation fog. All you need are two bottles with a narrow enough neck that you can stick an ice cube into the mouth.
http://starryskies.com/try_this/fog.html
Relative humidity, combined with air temperature, can be used to estimate the actual amount of moisture in the atmosphere, sometimes referred to as precipitable water.
http://www.ncte.ie/aecwinds/Measurements%20Composite.htm
We felt that there would even be different amounts of precipitation in the different areas of Evanston and Skokie that we live in.
http://www.collaboratory.nunet.net/timber/4thgradescifair2.htm
The purpose of this module is to introduce a number of cloud classifications, different types of precipitation, and the mechanisms responsible for producing them.
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/home.rxml
You will have created the conditions necessary for cloud formation: water vapor in the air, smoke particles for water to collect on, and cooling of the air by lowering the air pressure within a bottle.
http://www.chias.org/www/edu/activities/activity1/activity1.html