Demonstrate formation of sand dunes

Students watch demonstration of the effects of wind (from hair dryer) on plain sand, then sand with stones and grass, and record and justify conclusions. They then examine their thinking as they figured out how to justify each conclusion.

Materials:

2-speed hair dryer

2 flat pans

Small grass clumps

Angular stones

3 liters clean sand

Dustpan and broom for clean up.

1. Inquire what students know about sand dunes. Connect experiences with shapes of the dunes.

2. Explain that this experiment is to determine what factors affect the kinds of sand dunes the wind creates. Do the following experiment on a table, the floor, or outdoors.

a. Label the pans A and B. Place 1.5 liters of sand in each.

b. In pan B arrange stones and grass in different areas throughout the sand.

c. Turn the dryer on low speed. Hold it at a 45-degree angle, 10-cm from one end of pan A. Hold it for 1 minute. Record all observations. Repeat with pan B.

d. Change to high speed on dryer. Hold it at a 45-degree angle, 10-cm from one end of pan A for one minute. Record the effect. Repeat with pan B.

e. Sketch a diagram of the appearance of the sand in each pan.

f. Level the sand in pans A and B. Repeat steps c-e for each, blowing the air for 3 minutes each time.

Natural Science, http://server2.greatlakes.k12.mi.us/explorer/GLCbrowse/Natural^Science/index.html