STUDENTS SHOULD PROBABLY WEAR A PAPER FILTER MASK

Let's go outside again, to see what kinds of particles are most easily moved by wind. We'll make a mixture of materials ranging in size from clay to coarse sand. Now, we will set several shallow pans (like pie pans) at different distances from an electric fan. When we turn the fan on at a slow speed, and slowly pour a small steady stream of the mixture into the wind from the fan, we will see how wind blows the particles.

Note what kinds of particles are collected in the different pans. We will be able to see a pattern in the material blown by the fan, because the heavier particles will not blow as far from the fan as the lighter particles.

Repeat the activity, using faster fan speeds to see if the force of the wind makes any difference.

You will realize that this activity is similar to the way particles are actually moved across the earth's surface by the wind.