Return to Physics IndexWhat is Displacement? - Move Me Up!

Edwina Nelson Carter Elementary

5740 South Michigan

Chicago IL 60637

(312) 535-0860State Goal:

Number 4 - As a result of their schooling, students will have a working

knowledge of the processes, techniques, methods, equipment and available

technology of science.Objectives:

This activity is for all grades. Define displacement, volume, interpolation,

extrapolation, variable. Find the volume of an irregular solid.Materials Needed:

6-50 ml graduated cylinders

water

marbles

pebbles

ice cubes

graph paper/data table

sharpened pencils

rulersStrategy:

Working with a partner:

1. Pour 15 ml of water from the cup into the cylinder.

2. Carefully drop one of the marbles from the bag into the cylinder.

3. What is the level of the water in the cylinder now? Be sure and record

this information in the data area on the data table.

4. Carefully drop another marble into the cylinder. What is the level of the

water in the cylinder now?

5. Continue adding the rest of your marbles to the graduated cylinder and

recording the water level in the data area on the data table.

6. After you have added all 5 marbles and recorded the increase in water level

for each additional marble, graph the results of your investigation on the data

table.

7. Predict what the water level would be if you added a sixth marble.

8. Draw a picture of your experiment.

Now ask the students:

1. Why does the water level rise as a marble is added to the graduated

cylinder?

2. What was the volume of water in the graduated cylinder before you placed

any marbles in it?

3. Did the volume of the water change during the experiment? If it didn't,

then the volume of water is called afixed variable. Can you think of any

other variables that were held fixed during the experiment?

4. Using your graph, predict the volume reading of the graduated cylinder if

there are: 2 marbles in the cylinder, 4 marbles in the cylinder, 6 marbles in

the cylinder.

5. If the water level reading of the graduated cylinder is 45 ml, how many

marbles are in the liquid? At 48 ml? At 50 ml?

6. Write the numbers which involved interpolation and those that involved

extrapolation.Performance Assessment:

For the above questions, criteria used: Exceeds-5 to 6; Meets-4; Does not meet-

3 or below.

Scoring the data table: First examine the data table. If no information is

recorded, you must mark azeroin the box. If minimal data are recorded, you

must make a value judgment as to whether any of what is recorded would be useful

in understanding what the student did during the inquiry. If your answer is

"No", mark azero; if your answer is "Yes", mark aone. If the information

is useful in describing what took place during the inquiryandif several

experimental points are recorded in some organized manner, mark atwo. If the

student has additionally included some labelsorappropriate units, mark athree. Finally, if the appropriate units are in place and the student has

labeled the independent variable on the left and the dependent variable on the

bottom, mark afour.

Scoring the graph: Now examine the graph. If no information is recorded, mark

azeroin the box. If some minimal information is recorded, you must make a

value judgment as to whether or not what is recorded would be useful in

understanding what the student did during the inquiry. If your answer is "No",

mark azero. If your answer is "Yes", mark aone. If the student has

plotted some data points from the above tableandthe plotted points show a

lower left to upper right patternandhas provided at least one label, mark

atwo. If the student has all of the aboveandhas provided the appropriate

labels for both axesandan acceptable title, mark athree.

For data table and graph, criteria used: Exceeds-6 to 7; Meets-5; Does not

meet-4 or below.Conclusions:

The amount of water that an object replaces is called displacement. The volume

of water that an object displaces is equal to the volume of the object. The

volume of an irregularly shaped solid can be found by placing the object in

water and measuring the volume of water that the object displaces. If an object

displaces 10 ml of water, the object's volume is 10 ml.