NORTHWEST WEATHER WATCH

Experiment #5: Rainmaker

You can fill out this Lab Sheet on the computer and send it to your teacher's email address by clicking on the submit button when you are finished. Or click on this version, print it out, and fill it in by hand.

Question: What causes precipitation?

Discuss in your group what might cause the condensed water (cloud) to turn into precipitation (rain). On your Lab Sheet record your group's hypothesis.

Activity

In this activity you will be using the materials below to simulate one phase of Earth's water cycle - precipitation. We have already seen how water vapor (evaporated water in the air) condenses onto tiny particles when the air is cooled and forms a cloud. Your task will be to conduct a "precipitation simulation" and to formulate a hypothesis explaining how the condensed water (cloud) turned into precipitation (rain). You will need for each group:

The Experiment (Simulation) Procedure
  1. Place a pan of water onto the burner.
  2. Place 2 metal trash cans on either side of the burner.
  3. Place the cookie sheet on the 2 trash cans so that it forms a "ceiling" over the pan of water.
  4. Place the ice cubes on top of the cookie sheet.
  5. Heat the water and watch as the steam accumulates and hits the cool surface.
  6. Record your observations on the Lab Sheet.
Compare your simulation to Earth's water cycle. Which stage of the simulation represented.... Discuss in your group what happened to cause the condensation to turn into precipitation. Have you changed your hypothesis? Why or why not? Go to Hypothesis Revisited on your Lab Sheet and record your response.

Class Discussion

After your group has shared its findings with the class, decide upon your concluding hypothesis and record it on the Lab Sheet.

[Live from Earth & Mars]__________________________________________________