Measurement And Density

Topics: Volume, Length, Density Pages: 5 (851 words) Published: January 2, 2011
Measurement and Density

__ Purpose of this Lab
What is the goal of this lab? What question are you trying to answer, or what problem are you trying to explain?

Hypothesis
After reading the lab instructions - but before starting the lab - record your best “educated guess” about each experiment: Experiment 1: Which method of finding the density give you the least percent error and why? Experiment 2: After completing the first experiment, answer this question. Which block do you think has the highest density and why?

Experimental Design
List the materials used in this lab, and write a brief explanation of the procedures you followed. (You do not need to retype the procedure; simply summarize your procedures you used.) Procedures: Materials:

Data
On the following pages record the data you collect in the lab. Show all calculations performed in the data analysis. Calculating Percent Error In most cases, the values you obtain through experimentation will be slightly different from the documented accepted values. Using very precise measuring devices and utilizing the measuring devices correctly reduces the amount of error. The calculation for % error is similar to the calculation you would use to determine your average on an exam. The formula for % error is listed below. Calculate the % error for each substance in experiments 1 and 2. The accepted values are given in the table above. The experimental values are the values you found in the lab.

Percent Error = Experimental Value – Accepted Value x 100 Accepted Value Experiment-1 Measuring densities of the cubes using water overflow method. Mechanical Balance Red Cube Green Cube

No. 1

Blue Cube

No. 1 2 3 4 5 Average Volume Cube Red Green Blue Element Iron Copper Zinc

Graduated Cylinder Red Cube Green Cube

Blue Cube

Mass (in grams)

Volume (cm3)

Density( g/ cm3) =Mass/Volume

Element Present

Standard Density (g/cm3) 7.8 8.9 7.1

Calculated Density (g/cm3)

Experiment-2 Measure densities of the cubes using Vernier Calipers and Digital Weighing balance. Digital Balance Red Cube Green Cube

No. 1 2 3 4 5 Average mass

Blue Cube

No.
Length (L)

Vernier Caliper Red Cube
Width (W) Height (H) LxWxH

1 2 3 4 5 Average Volume Green Cube No. 1 2 3 4 5 Average Volume Length (L) Width (W) Height (H) LxWxH

Blue Cube No. 1 2 3 4 5 Average Volume
Length (L) Width (W) Height (H) LxWxH

Cube Red Green Blue

Mass (in grams)

Volume (cm3)

Density( g/ cm3) =Mass/Volume

Element Present

Element Iron Copper Zinc

Standard Density (g/cm3) 7.86 8.96 7.13

Calculated Density (g/cm3)

Data Analysis
Analyze the data you collected in the lab. Support your calculated densities by showing the calculations that lead you to your results. Calculate your percent error and compare your percent error from experiment 1 to your percent error in experiment 2.

Conclusion
After conducting the experiment, how would you now explain the problem(s) or answer the question(s) raised when you described the purpose of the lab? Do your results support your hypothesis? Why or why not? Be sure to base your answer on the data you collected. Consider whether your conclusion is the only explanation for the data you collected, or if there could be alternate explanations.

Post Lab Questions
Answer the following questions before submitting your report to your teacher. Show all work in all questions requiring calculations. Use the following density table when needed. Density Table Substance Aluminum Oak Pine Polypropylene PVC Steel Water Lead Bismuth Density (g/cm3) 2.70 0.75 0.42 0.92 1.40 7.9 1.0 11.4 9.78

1. Suppose you were asked to find the density of a metal object that appears to be a cube. You notice...