TITLE:   The Drinking Bird

AUTHOR:  Clark Brean, Lebanon Union H. S., Lebanon, Or.

GRADE LEVEL/SUBJECT:  (9-12) Physics

PURPOSE:  To investigate the operation of a toy drinking
bird.

RESOURCES/MATERIALS:
Drinking bird
250 ml beaker
Water

OBJECTIVE:
     Toys often illustrate fundamental physical principles.
The toy drinking bird is an example.  The challenge for you
in the lab is to discover why the drinking bird functions.

ACTIVITIES AND PROCEDURES:

1.   Set up the toy drinking bird with a beaker of water so
     that the bird will cycle.  Be sure the bird beak
     touches the water with each cycle.Q  You may need to
     adjust the fulcrum to be sure the bird cycles smoothly.

     NOTE:  As the instructor, you might want to be sure you
     have all birds cycling correctly before the lab to save
     time.

2.   After the bird starts "drinking," study its operation
     carefully.  Your goal is to explain how it works.  As a
     final product, I would like an outline that explains
     step by step, one full cycle of the bird's movement.

OPTIONAL QUESTIONS

NOTE:  You may include these questions to help lead the
students to the explanation of the cycle or you may hold
them for yourself and use them to guide students that become
stuck.

1.  What causes the fluid to rise up the toy bird's neck?

2.  What causes the bird to dip?

3.  What causes the bird to make itself erect?

4.  What is the purpose of the fuzzy head of the bird?

5.  Will the bird continue to drink if the cup is
    removed? Explain.

6.  Will the relative humidity of the surrounding air
    affect the rate of dipping of the bird?  Explain.

7.  Will the bird dip faster indoors or outdoors?  Why
    will this be so?

8.  Give three conditions that will cause the bird to
    fail to operate.

9.  Give at least one practical application of the method
    of operation of the drinking bird.

10. How does the temperature of the water in the beaker
    affect the rate of cycling of the bird?