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Natural Science - Year II

Unit 34: Welcome to Natural Science Year Two

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Lab Assignment for Unit 34


This Unit's Homework Page History Lecture Science Lecture Lab Parents' Notes

Unit 34 Laboratory Activity: Measurement and Accuracy

Goal: Identify Proper Experimental Techniques

Pre-Lab Preparation

Read the entry on Lab Work for this course.

Then read the following sections in the Student Survival Guide:

  • Doing Labs
  • Writing Lab Reports

Be sure that you understand the requirements for lab credit:

  1. How many labs are required to receive lab credit for the course?
  2. What is the lab permission letter? Where do you find it? Where do you send it?
  3. Where are the safety procedures located? Did you read them carefully? What should you do if you don't understand how they apply to a particular lab?
  4. What equipment should you have to do most of the labs for the course?
  5. Where can you find suppliers for the equipment?
  6. What are the three kinds of direct research you can do?
  7. What are the five parts you should include in each lab report?

Make notes on each part of the lab report, and especially on anything that doesn't make sense to you. Bring any questions you have on lab expectations to class.

A good lab report data section includes all your raw data measurements, sample calculations, graphs if it is important to show a trend in the data, the results of your calculations, and a summary of the importance of the data to your goal.


Goal: To learn how to measure something several ways and determine errors in observation.

Materials:

Procedure:

Part 1

Part 2

Report

Follow the appropriate lab format for presenting information about your hypothesis or goals, your procedure (especially identifying any changes you made to the suggested lab procedure above). Create sections for your raw data and calculated data:

  1. Lay out your data in tables like this:

    Trial #Measurement
    15.1
    15.2
    14.9
  2. Calculate the average value: (5.1 + 5.2 + 4.9)/3 = 15.2/3 = 5.06"
  3. Add another colum to the table and calculate the difference between the measured value and the average value.

    Trial #MeasurementDeviation
    15.10.04
    15.20.14
    14.90.07
  4. Determine the percentage of error for each measurement.

    Trial #MeasurementDeviationPercentage error
    15.10.04 0.04/5.06 = 0.0079 = 0.79%
    15.20.140.14/5.06 = 0.027 = 2.7%
    14.90.070.07/5.06 = 0.014 = 1.4%

Include conclusions about the accuracy and errors of your measurements and a specific suggestion for increasing accuracy and reducing error.