06-Mar-2017: Propagated uncertainty in measurements

Lab 6: Propogated uncertainty in measurements

Name: Kevin Nguyen

Lab Partners: Jode Rodriguez, Kevin Tran

Date performed: 06-Mar-2017

Purpose: The purpose of this lab is to learn how to calculate propagated uncertainty and apply them in the calculations to find the density and propagated uncertainties of two cylinders with unknown densities.

Theory/ Introduction: In order to find the density of those cylinders, we needed to find mass and volume of the cylinders. We found mass easily by weighing it on the electronic scale. Volume, on the other hand, must be calculated by finding the diameter and height of the cylinders. In our volume calculation, we made sure to divide diameter by 2 to represent radius. Using a caliper, we measured the cylinder's diameter and height in order to find volume. We also kept in mind that the caliper and electronic balance measured + or - 0.01 cm from the actual diameter, height, and mass of the cylinder. These numbers are important since those numbers are propagated uncertainties that we use to calculate the uncertainty of its density.

Summary: We grabbed two cylinders and measured their masses as well as their diameter and height.

We measured the diameter of cylinder 1.

We also measured the height of cylinder 1. 

And we measured the height and diameter of cylinder 2. 

Unfortunately, we did not have a picture of us measuring their masses.

Measured Data:

Calculated results:

Explanation of analysis: This is addressed in theory/ introduction

Conclusion: When we checked what material the cylinders are made out of, cylinder 1 is made out of zinc and cylinder 2 is made out of aluminum. For the density of cylinder 1, although we got 7.33 plus or minus 0.081 g/cm^3, the accepted value for density of zinc is 7.140 g/cm^3. Also, for the density of cylinder, although we got 2.90 plus or minus 0.0345 g/cm^3, the accepted value for aluminum is 2.70 g/cm^3. The reason why we have error in our results was because we did not take into account the hook that was connected on the top of the two cylinders in our measurements for volume. Another source of error may have stemmed from our assumptions that the cylinders were pure zinc or aluminum. Since there may have been other metals inside the cylinder, as a result, our calculated density isn't accurate. The errors that we have committed were systematic errors.