To let each student become familiar with measuring with a triple beam balance and to develop critical thinking skills. Secondly, to introduce student to a technique of data analysis using linear regression.

 

 

 

Each group of two will receive 10 envelopes containing identical index cards.

 

NOTE: If there are not enough balances, one group at a time is to measure their envelopes. It should not take more than 5-8 minutes get the 10 mass measures. After each group is through with the balance, they can return to their own computer to complete their analysis and let a second group use the balance.

 

After zeroing your triple beam balance, measure the mass of each of the 10 envelopes. In the table below, record the number of cards identified as being in each envelope and the sealed envelope's mass. Do NOT open any of your envelopes. Two envelopes will be identified only by letters. Measure and record their masses and then place their values in the last two rows of the data chart.

 

Envelope	# or letter	Mass (g)
1
2
3
4
5
6
7
8
9
10

 

 

 

EXCEL will now graph your data. Minimize your browser, double click My Computer, double click the shared drive called colwell/bay on Lederman, double click your period's folder and then finally double click 1-mass.xls. You will most likely be asked to open the file as "read only" - that is fine. As soon as the file is open, use File Save As to rename the file as

 

 

in your period's folder. This copy of the file now belongs uniquely to your group. Remember that there are to be no spaces in the file name.

 

Input your values for the number of cards and the mass of each envelop into the spreadsheet. (Do not enter the information from the two envelopes that have letters instead of numbers). As you enter your data, its graph will grow. When your graph is finished, be certain that any points that are obviously out-of-line have been rechecked for accuracy - either in measurement, or for a mistake in typing. Resave your EXCEL sheet and get a printout from your teacher.