Uncertainty of measurements & significant figures

AI Thread Summary
The discussion centers on calculating the uncertainty of a measurement when converting from inches to meters using a tape measure. The conversion factor of 1 meter equaling 39.3701 inches is applied, with the tape measuring in increments of 0.0625 inches. The uncertainty in the measurement is determined to be ±0.0625 inches, which translates to approximately ±0.00158 meters. The last certain digit for reporting the measurement in meters is suggested to be 1.00, indicating precision to two decimal places. The conversation clarifies the importance of selecting the nearest mark on the tape for accurate measurement.
ELLE_AW
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Homework Statement


This conversion factor 1m = 39.3701 inches was used, when measuring a tape that had inches on it to a full meter. The measuring tape increased by 0.0625 inch increments, so the 1 meter (39.3701) was estimated to be in between the 39.3125 and 39.3750 on the actual measuring tape.
Based on this what is uncertainty of my measurement in meters? What is the last certain digit? What sig figs would would the meters be reported to accurately (e.g. 1.0 or 1.00) ?

Homework Equations


conversion factor: 1 m = 39.3701 inches

The Attempt at a Solution


I think the meter should be written as 1.00

I think the uncertainty would be 0.0625 inches x 1 m / 39.3701 inches = 0.00158 meters

I feel like I"m wrong though.
 
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ELLE_AW said:
when measuring a tape that had inches on it to a full meter.
Not quite sure what this means.
Is the idea that we are trying to measure off a distance of one metre using this tape? If so, we have to choose which of the ##\frac 1{16}##" marks to use.
 
haruspex said:
Not quite sure what this means.
Is the idea that we are trying to measure off a distance of one metre using this tape? If so, we have to choose which of the ##\frac 1{16}##" marks to use.

Figured it out.

Yes, measuring a distance of 1 meter using this tape that has units of inches. Yes, I just wanted to calculate the uncertainty, but it's basically the smallest increment by which the measuring tool (tape in this case) increases... so +/- 0.0625 inches.
 
ELLE_AW said:
Figured it out.

Yes, measuring a distance of 1 meter using this tape that has units of inches. Yes, I just wanted to calculate the uncertainty, but it's basically the smallest increment by which the measuring tool (tape in this case) increases... so +/- 0.0625 inches.
I would assume that the tape user is able to select the nearest mark on the tape.
 
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