Challenge: To design procedures for making precise and accurate measurements of very thin objects like paper, hair, etc.
Parameters: Your team will develop (and record) a procedure for measuring very thin objects. You may only use materials and tools provided by Mr. J. You may not purchase anything or bring any tools from anywhere else.
Scoring: Your procedure will be scored based on the precision and accuracy of your measurements and your estimate of your uncertainty, as follows:
| % difference object one | + | % difference object two | + Confidence factor*
* Confidence factor: add one penalty point for incorrect uncertainty. Incorrect uncertainty is an absolute uncertainty more than a factor of 3 away from your actual percent difference.
Rank will be based on score, with lowest score earning highest rank.
Physics: A measuring device can only be as accurate as the standards used in its construction. Its precision depends on the fine-ness of its markings and your ability to interpolate between those marks. Another factor is the material properties of the device. Most materials expand and contract with temperature changes or rough use.
Extensions: The biggest factor is going to be your technique. Practice makes perfect. Make sure you can reliably use your measuring device(s). Find out how averaging multiple measurements of the same dimension can be used to reduce uncertainty.
Help/Hints: Have each member of the group try to independently find the measurements of an object, then compare within the group. What factors can cause disagreement? What does that tell you about uncertainty?
Quiz Topics: Measurement
Uncertainty
Scientific communication
Online Text: chapter 1