Methods of Measurement

Transcription

1 PARADISE VALLEY COMMUNITY COLLEGE PHYSICS COLLEGE PHYSICS 1 LABORATORY Methods of Measurement EQUIPMENT NEEDED: 2-meter sticks, 1-meter sticks, Vernier and micrometer calipers, weight scales, metal and wood cylinders, metal cubes. INTRODUCTION: In the laboratory introduction section, there was a discussion about the statistical treatment of laboratory data. In this exercise you will be asked to carry out some measurements and determine the average values of your measurements. OBJECTIVES 1) To become familiar with some metric units; 2) To learn to use vernier and micrometer calipers; 3) To learn proper use of significant figures; PROCEDURES 1) Using the 2-meter (and/or 1-meter) stick, measure the length and width of your laboratory table. Make each measurement at least five times at different places on the table. Estimate each measurement to the nearest 0.1 mm. Calculate the average length and width of your table. Then, calculate the area of the table and determine its average value. Enter all your values in the table provided. 2) For the cylinder (either aluminum, brass, copper, lead, wood, or zinc), use the vernier caliper to measure the length and the micrometer caliper to measure the diameter (your instructor may allow you to use the meter stick instead to make the measurements). Calculate the volume of the cylinder. Measure the mass of the cylinder, and calculate the density of the material. Make 3 measurements each of the length, diameter (radius), and mass. Calculate the 1

2 average length, diameter (radius), mass, volume, and density. (The volume of a cylinder is V = πr 2 L. The formula for density is ρ = m/v, where ρ is Greek rho. ) Enter all your numbers in the table provided. 3) For the metal cube (either aluminum, brass, copper, lead, or zinc), use the vernier caliper to measure the length, width, and height of the cube (your instructor may allow you to use the meter stick instead to make the measurements). Calculate the volume of the cube. Measure the mass of the cube, and calculate the density of the material. Make 3 measurements each of the length, width, and height. Calculate the average length, width, height, volume, and density. (The volume of the cube is V = LxWxH. The formula for density is ρ = m/v, where ρ is Greek rho. ) Enter all your numbers in the table provided. Main Points to Consider for this Lab: 1) Don t forget to include units! 2) Include in your lab write-up a table containing the relevant measurements/calculations for the area of the lab table. 3) Include in your lab write-up a table containing the relevant measurements/calculations for the density of the cylinder. 4) Include in your lab write-up a table containing the relevant measurements/calculations for the density of the metal cube. 5) When calculating the density of your cylinder, be sure to use units of grams for mass, centimeters for radius, and centimeters for height in your table. 6) When calculating the density of your metal cube, be sure to use units of grams for mass, centimeters for length, centimeters for width, and centimeters for height in your table. 7) Compare your calculated density to the actual value shown in the table below for the material you used. Explain what the reason could be for any discrepancies in your final value to the actual value. 2

3 Material Density=ρ (g/cm 3 ) Wood Aluminum 2.70 Zinc 7.14 Brass 8.55 Copper 8.92 Lead Table 1: Density for different substances. Length=L Width=W Area=A (cm) (cm) (cm 2 ) average average average Table 2: Table for area calculation for a lab table. Mass=m Diameter=D Radius=r Length=L Volume=V Density=ρ (g) (cm) (cm) (cm) (cm 3 ) (g/cm 3 ) average average average average average average Table 3: Table for density calculation for a cylinder. 3

4 Mass=m Length=L Width=W Height=H Volume=V Density=ρ (g) (cm) (cm) (cm) (cm 3 ) (g/cm 3 ) average average average average average average Table 4: Table for density calculation for a metal cube. 4

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