A Unit of SI (Laboratory)

A Unit of SI (Laboratory)

Purpose:  In this activity, you will find the density of an irregular solid.

Problem Statement


Null Hypothesis:


1. Use the balance to measure the rock’s mass. Record your measurement in the data table.

2. Pour 50 mL of water into a graduated cylinder. Record the starting volume in the data table.

3. Gently slide the rock into the water. Measure the volume of the rock plus the water. Record the result.

4. Subtract the original volume of water in the graduated cylinder from the volume you found in Step 3. The result is the volume of the rock. Record your result.

5. To calculate the density of the rock, divide its mass by its volume. Record the result.

6. Repeat Steps 1 through 5 and record your data.


Measurements and Calculations


Trial 1

Trial 2

1. Mass of object (g)



2. Volume of water (mL)



3. Volume of water plus rock (mL)



4. Volume of rock (cm3)



5. Density of rock (g/cm3)




   When you put the rock into the water, the volume in the graduated cylinder
changed. Would the change in volume be different for different objects? Why?

   Why did you repeat your measurements?

Conclusion (This is must be in paragraph form and must answer all seven questions)

  1. What was investigated?
  2. Was the hypothesis supported by the data?
  3. What were the major findings?
  4. How did your findings compare with other researchers?
  5. What possible explanations can you offer for your findings?
  6. What recommendations do you have for further study and for improving the experiment?
  7. What are some possible applications of the experiment?