Introduction to Propogation

Purpose:
The purpose of the lab is to introduce the concept of propagation, or the level of uncertainty that comes from the limitations of the precision of the equipment.

Equipment Used: 

The caliber was used to measure the diameter and the height of aluminum, copper, and steel cylinders. The scale was used to find the mass of the cylinders. After the density of the cylinders was calculated, the mass of an unknown hanging weight on two strings each at a certain tension. A tension meter was used for each string. The level angle finder was used to find the angles of both strings.

Data Collection: 

The caliber had an uncertainty of ±.01cm, so for the cylinder diameter and the cylinder height there was this amount of uncertainty. The scale used had an uncertainty of ±.1g. 

For the calculation of the unknown hanging mass one of the tension meters had an uncertainty of ±.5N and the other tension meter had an uncertainty of ±.2N. The level angle finder had an angle uncertainty of ±2 but in radians it is ±.288.

Calculations:

The aluminum cylinder had a density uncertainty of ±.1318, the copper cylinder had a density of uncertainty of ±.5816, and the steel cylinder had a density of  ±.3096.

The unknown mass had an uncertainty of ±.146kg.

Conclusion:
The uncertainty values for the density of the cylinders was very low, each one had an uncertainty of less than 2%. That is very accurate considering the units of grams and centimeters. The unknown hanging mass had a larger uncertainty value of 14.6% and that is very high.The cause for the high uncertainty came from the uncertainty in the tension meters, one of which had an uncertainty of .5N.

 Sincerely,

Swaggy C