Physics Activity - Measurement
Yet Another Simple Measurement1
Discussion:
Ok - no fooling around this time. I've certainly learned my
lesson! This is serious! Everyone will use the same ruler this time,
by golly...
In this activity, you will individually measure the length of an
object supplied by your teacher. Then you will compare your
measurement with your classmates' measurements and decide on the best
estimate of the object's length.
Before you attempt this activity, be sure that you have read the
material on measurement -
particularly "How to Analyze a
'Measure the Value of ...' Experiment".
Equipment:
Per class:
an object to measure (supplied by your teacher)
|
a metric measuring tape
|
|
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Procedure:
- Before your begin, write a brief description of this activity
in your lab notebook.
- When it is your turn to measure the object, record your
measurement in your lab notebook in a data table similar to the
data table below. Use the number of significant digits that you
feel is appropriate.
- Write your name and result on the board as directed by your
teacher.
- Record your classmates' measurements in your lab
notebook.
Results:
- Your teacher will tell you when and how to report your
measurement on the board.
- Discuss the class' results with your classmates. Come to an
agreement on a best estimate for the length of the object,
including the appropriate number of significant digits to
use.
- Calculate and record an uncertainty
interval for your best estimate.
- Your teacher will tell you the "accepted value" of the length
measurement. Record it in the data table.
- Calculate a "t-score"
for the class'best estimate and the accepted vallue.
- Calculate and record the percent of difference between the
class' result and the accepted value.
- Discuss these results with the class.
Conclusions:
In your lab notebook, record the results of this activity, as well
as any other results or conclusions reached by the class. Also,
answer the following questions:
- Based upon our criteria,
how well does the class' measurement agree with the accepted
value? Why do you think this happened?
- How did the measuring tape affect the precision
of your results?
- How did the measuring tape affect the accuracy
of your results?
- Was there any random
uncertainty in the measurements of this activity? How did it
arise?
- Was there any systematic
uncertainty in the measurements of this activity? How did it
arise?
1based on "Activity 2: Measurement with the ...
Meterstick" in the Pasco Significant Figures Set (ME-9849)
last update June 6, 2005 by JL Stanbrough