MATERIALS: 1 eye dropper, 1 large glass jar ( from a used up 2 lb strawberry jam jar or any large jar with a safety button on top of cap. [ to indicate that the product has not been opened or spoil; just like the caps on baby food jars, that has a safety button in the middle]
First, when you have the student do the experiment, just use the rubber part of the eye dropper, then have the student repeat the experiment with the whole eye dropper. Using the whole eye dropper, observe what happens to the air inside the nozzle of the eye dropper.
PROCEDURE AND OBSERVATION:
1. Fill jar to the very top, you may want to try this in the sink.
2. Take the rubber top of an eye dropper. Now, holding it between the thumb and index finger, try to float rubber eye dropper.
3. The eye dropper must just be barely floating. To do this, use the thumb and index finger and squeeze out just the right amount of air; so that it barely floats, it may take you several tries.
4. Now that the eye dropper is barely floating, top of the jar with water, so that the water is just about to overflow.
5. Put the safety cap on the jar, now firmly press down on the button of the safety cap.
6. Now what happens to the rubber eye dropper?
7. Can you control the rubber eye dropper?
8. Try holding the eye dropper at the bottom; is this possible?
9. Try floating the eye dropper half way down; is this possible?
QUESTIONS:
1. Define force-
2. Define pressure-
3. Are there any forces within the water? Explain.
4. List several forces. Give an example of each.
5. What is buoyancy?
6. Buoyancy is directly related to ________________.
7. State Archimedes' Principle.
8. How is density of a liquid related to specific gravity of a liquid?
9. When will an object float in water?
10. The volume of a liquid is _____________. The volume of a gas is___________.
11. The shape of a liquid is _____________. The shape of a gas is ____________.
12. When all the air was squeezed out; what happened to the eye dropper?
13. You know that the eye dropper has to have some air in order to float. When is sinks it has hardly any air.
14. Do you think that something to the air inside the eye dropper, when the button of the cap is pressed down? Explain your answer.
15. What is the basic formula for the pressure in a liquid?
16. Measure th height of the jar; What is the pressure at the bottom of the jar?