PASCO ME-9849 Significant Figures Set - Manual (Page 20)

Significant Figures Set Density Calculations
18 ®
6. Write the following data table on the board.
Procedure
1. Measure and record the length, width, and height of the sample object. Use a different side of
the four-sided meter stick to measure each dimension of the sample object.
2. Calculate the volume of the object.
3. Measure and record the mass of the object using the balance assigned to you by your teacher.
4. Enter your measurements and calculations in the data table on the board.
5. Write the density on the data pointer. Tape the data pointer to the corresponding value on the
number line.
6. The teacher will place the accepted value of the density on the number line.
Post-Lab Discussion
Ask students to present their values of length, width, height, and mass. Make sure they address the
reasoning behind the precision of their measurements. Have them also discuss how they
maintained precision through the calculation.
Have students observe the data table. Ask students what determines the precision of the density.
Direct students to realize that the least precise measurement in their calculation determines the
precision of the density. As a class, make any necessary changes to the calculations.
Questions:
1. What determines the precision of the density calculation?
2. Why is it important to use the same technique to measure each length? For example, if you
remember to take into account parallax for one measurement and you do not for the other
measurements, how will this effect your final density calculation?
Group # Length (cm) Width (cm) Height (cm) Mass (kg) Volume
(cm
3
)
Density (kg/
cm
3
)
1
2
3
4
5
6
7
8