# Physics Experiment 1 Errors Uncertainties and Measurement

Laboratory Report

Department of Math and Physics

College of Science, University of Santo Tomas

Abstract

With the use of the ruler, vernier caliper, micrometer caliper and electronic gram scale, the group was able to acquire different sets of measurements by measuring the sphere of unknown composition. The group then was able to compute its mean diameter, average deviation, average deviation of the mean, volume, mass and % percent error for density in SI unit. Then, the members of the group measured the thumb of each other using the ruler and recorded the data in inches.

1. Introduction

During the ancient times, there were many types of measurements used but it was highly unreliable. It was during the late 1700s to 1800s when the SI unit was found and it became the standard of measurement.

The experiment was designed for studying and analyzing errors and how they occur in an experiment, computing the average deviation, mean and the set of average deviation of the mean, familiarizing and comparing the values produced by the vernier caliper, micrometer and the foot rule, and determining the density of an object given its mass and its volume.

2. Theory

In order to prove that no matter how precise your measurements are, there will always be an error. Also, in this experiment, it also aims to prove that the use of body as a tool for measurement will not be precise.

3. Methodology

For this experiment, the group used a ruler, vernier caliper, micrometer caliper, electronic gram balance and a sphere of unknown composition.

In order to determine the diameter of the sphere, measuring tools such as ruler, vernier caliper and micrometer caliper were used. With the ruler, different angles were used to obtain the diameter of the sphere.

With the vernier caliper, the sphere was inserted between its jaws and the screw clamp was closed to prevent the jaws from moving. The diameter of the sphere was determined by the measurement of the main scale added with the measurement of the vernier scale that forms a line with the main scale.

[pic]

Figure 1: Vernier caliper and its parts

With the micrometer caliper, the ball was placed between the anvil and the spindle making sure that the balls was secured in place. Once the ball was secure, the measurements from the main scale and the micrometer scale where then added to get the diameter of the sphere.

[pic]

Fig 2. Micrometer Caliper and its parts

Ten trials were done for each of the measuring instruments. When the data was complete, the following values were computed: Average Diameter, Average Deviation, Average Deviation of the Mean, Volume, Experimental Value of Density and the Percent Error of Density.

4. Results and Discussion

Figure 1: Using foot rule

|Diameter of Sphere (cm) | |Trial |Measurement |Difference from Average | | |of Diameter |Deviation | |1 |1.90 cm |0.06 | |2 |1.80 cm |0.04 | |3 |1.85 cm |0.01 | |4 |1.80 cm |0.04 | |5 |1.90 cm |0.06 | |6 |1.80 cm |0.04 | |7 |1.85 cm |0.01 | |8 |1.82 cm |0.02 | |9 |1.83 cm |0.01 | |10 |1.82 cm |0.02 | |Mean Diameter |1.84 |0.03 | |Average Deviation(a.d.) |0.003 | |Average Deviation of the Mean (A.D.)...

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