Ethan+Lab+1

Purpose:

The purpose of this lab was to show the accuracy of the different measuring tools available to us, as well as use the two fundamental measurements, length and mass.

Hypothesis:

It is hypothesized that the measurements gathered with our tools will be close to the actual measurements, and will therefor have a low percent error.

Apparatus:


 * Meterstick
 * English SI Ruler
 * Caliper
 * Micrometer
 * Cylinders
 * Spheres
 * Balance

Procedure:

First, one of the cylinders was measured for length and diameter with the caliper. Radius was found by d/2. Then, the cylinder was measured with the balance to find its mass. The same was done for the second cylinder.

Secondly, one of the spheres was measured for its length and diameter with the micrometer. Radius was found by d/2. Then, the sphere was measured with the balance to find its mass. The same was done for the second sphere.

Data:

Figure 1.1 Cylinder 1
 * Trial || Length L || Diameter D || Radius R ||
 * No. || cm || cm || cm ||
 * 1 || 9.71 || 1.64 || 8.2 ||
 * 2 || 9.71 || 1.64 || 8.2 ||
 * 3 || 9.71 || 1.64 || 8.2 ||

Volume: 21cm^3 Mass: 22.289g Experimental mass density: 1.1 g/cm^3 Accepted mass density:1.24 g/cm^3 Error:.14 g/cm^3 % Error: .11%

Figure 1.2 Cylinder 2


 * Trial || Length L || Diameter D || Radius R ||
 * No. || cm || cm || cm ||
 * 1 || 7.63 || 1.61 || 0.81 ||
 * 2 || 7.63 || 1.61 || 0.81 ||
 * 3 || 7.63 || 1.61 || 0.81 ||

Volume: 16 cm^3 Mass: 17.401g Experimental mass density: 1.12 g/cm^3 Accepted mass density: 1.24 g/cm^3 Error: .12g/cm^3 % Error: 9.7%

Figure 2.1 Sphere 1


 * Trial || Length L || Diameter D || Radius R ||
 * No. || cm || cm || cm ||
 * 1 || 2.55 || 2.55 || 1.28 ||
 * 2 || 2.55 || 2.55 || 1.28 ||
 * 3 || 2.55 || 2.55 || 1.28 ||

Volume: 8.34 cm^3 Mass: 20.062g Experimental mass density: 2.41g/cm^3 Accepted mass density: 2.7g/cm^3 Error: .294 g/cm^3 % Error: 11%

Figure 2.2 Sphere 2


 * Trial  ||   Length L   ||   Diameter D   ||   Radius R   ||
 * No.  ||   cm   ||   cm   ||   cm   ||
 * 1  ||   1.42   ||   1.42   ||   0.71   ||
 * 2  ||   1.42   ||   1.42   ||   0.71   ||
 * 3  ||   1.42   ||   1.42   ||   0.71   ||

Volume: 1.50cm^3 Mass: 3.049g Experimental mass density: 2.04g/cm^3 Accepted mass density: 2.56g/cm^3 Error: .525g/cm^3 % Error: 20.5%

Analysis:

Volume of a cylinder: π r^2 h (π(8.2) ^2 x 9.71 = 16 cm^3)

Volume of a sphere: 4/3π r^3 ( 4/3 π(.71) ^3 = 1.50 cm^3)

% Error: (abs(expected value – experimental value)/expected value) x 100 (abs(2.56g/cm^3 – 2.04g/cm^3)/2.56g/cm^3) x 100 = 20.5%

The high percent error could be due to faulty measuring equipment, or the own personal fault of a group member in using the measuring tools.

Conclusion:

<span style="font-family: Times New Roman,serif;">Contrary to the hypothesis, the percent error of 1.2,1.3, and 1.4 were quite high (>5.0%).