Accuracy & Precision Lab
Name__________________________
25 Points
Period_______Date_______________
Background: Define and explain the following before beginning the experiment (3 points):
Accuracy:
Precision:
Uncertainty:
Materials:
triple-beam balance
10 mL graduated cylinder
Celcius thermometer
50 mL graduated cylinder
centimeter ruler
water
coin
paper
Procedure:
1. Using the triple-beam balance, measure the mass of the coin (or key) and record in the data
table using the correct number of significant digits and unit. Always remember to determine
the precision of the instrument first. (Repeat two more times)
2. Using the centimeter ruler, measure the length and width of this lab sheet and record in the data
table using the correct number of significant digits and unit. (Repeat two more times)
3. Using the Celsius thermometer, measure the air temperature in the classroom and record in the
data table using the correct number of significant digits and unit. (Repeat two more times)
4. Using the 50 mL graduated cylinder from your drawer, fill it with any amount of tap water and
measure the volume of the water. Record the amount in the data table with the correct number
of significant digits and unit. Repeat two more times, targeting the same volume.
5. Using the red 10 mL graduated cylinder from your drawer, fill it with any amount of tap water
and measure the volume of the water. Record the amount in the data table with the correct
number of significant digits and unit. Repeat two more times, targeting the same volume.
Data Table: (12 points)
Instrument
Measurement
Trial 1
Triple-beam balance
Mass of coin (g)
Centimeter ruler
Length of paper (cm)
Width of paper (cm)
Celcius thermometer
Air temperature (oC)
Graduated cylinder
(50 mL)
Graduated cylinder
(red - 10 mL)
Water Volume (mL)
Water Volume (mL)
Results
Trial 2
Trial 3
Uncertainty
+/- precision unit
Questions:
1. Were your numbers for each measurement precise? Explain (1 pt) _____________________________
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2. Which instrument would be more precise for measuring volume of a liquid, a beaker or a graduated
cylinder? (1 pt) ______________________________Why? (1 pt) ______________________________
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3. Volume can be measured in units of cm3 or mL. (2 pts)
When would you use cm3? ________________________________________________________
When would you use mL? _________________________________________________________
4. Is a precise measurement always accurate? Explain your answer. (2 pts)
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5. List a variable that might have affected the accuracy of your measurements: (1 pt)
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6. List a variable that might have affected the precision of your measurements: (1 pt)
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