6-March-2017: Propagated Uncertainty Lab

Lab#6: Propagated Uncertainty

May Soe Moe

Lab Partners: Ben Chen, Steven Castro

6-March-2017

Objective: To learn using caliber and to calculate the propagated error in density measurement

Introduction: There are random errors when we measure things, things that we cannot control. We cannot know its exact measurement such as mass, weight, and height of objects. We expect them to be off by several decimals, give or take. In the case when we know we will make errors during our labs, we will calculate how much our error and uncertainty should be. The goal of this lab was to know the uncertainty of our measurement of density through calculations of propagated uncertainty. We calculated uncertainty by doing partial derivatives of our known equation. For this lab, we learned how to use calipers, which can let us measure to two decimal places. We used calipers to measure the height and diameter of two cylindrical metals: Zinc and Aluminum. We also used electric balance to measure the mass of the metals. And we computed the volume and density of each metal, which we found partial derivatives of the equation Density= Mass/ Volume.

Experimental Procedure:
(1) We measured the mass of two metals using electric balance and recorded it.

Measuring the Mass of the Metal Using Electrical Balance

(2) We measured and recorded the height and diameter of two cylindrical medals using caliper. 

Measuring Device- Caliper

             

(3) We calculated volume and density using the recorded data and our known equations of volume and density.

Recorded Data and Calculating Volume and Density

(4) Once we got our density and volume values, we calculated their uncertainty by finding partial derivatives as below:

Conclusion:

Here is the uncertainty values we got from calculation: