Lab 1-2 Indirect Measurement

In this experiment, i found that i was able to calculate the thickness of the aluminum foils, as well as the diameter of the copper wire with minimal percent error. The percent errors of the test were; regular foil: -7.6%, heavy duty foil: -17.86%, and for the copper wire: -6.45%. To find the thickness of the aluminum foils, I used what ! know about aluminum, (the density), determined the mass, using the scale, and measured the length and width the best I could. From there, I just used the density formula, and did the simple math do determine themissing variable (the "height" of the aluminum foil).
The copper wire, however, was a little more difficult in coming up with a solution. Assuming that the width and height of the copper wire were the same, (because they were both the diameter, instead of having two separate variables, (X & Y), I had two of the same variable, (2X).. From there, i used the same technique as before, only with different equations and different variables.
When using a ruler, and water displacement to calculate the thickness, you can read them inaccurately. That is why there are limitations to those techniques.
When there are a large number of decimals, we cannot be confident that this is an exact measurement. if we were to use a calculator, it does not know that we are taking measurements on tangable items, and therefore, and it may give a nonterminating decimal. This of course makes no sense, because a measurement has to terminate. So, in this case, we have to round the number, thus, making it slightly inaccurate.
Some sources of error in how i conducted the experiment are: 1. The foil may not be 100% aluminum, and thus could have a different density. 2. Using a ruler, we might not measure correctly. 3. The foil may not be a perfect rectangle, so  when measuring, we would have to account for, and subtract the part of the "rectangle" that is missing.
We could use the same method of finding the diameter of the wire in a power line. The only extra steps we would need to include would be determining what materials are included in the power line (copper, Rubber, etc.) and what percentage of the power line they are. Other than those steps, we could use the same simple equations to solve that problem.