1/28/09

Post date: Jan 27, 2009 3:25:21 PM

Bell Ringer: When making a measurement, what determines how accurate or precise our measurement is?

• • Significant Figures

    • precision - exactness of a measurement

    • accuracy - how close to the actual value

    • sig figs show the precision of a measurement

    • Rules

      • 1. Non-zero digits are ALWAYS significant

        2. All final zeroes after the decimal are significant

        3. Zeroes between other significant digits are significant

        4. Zeroes used only for spacing the decimal are NOT significant

    • Example problems

• • • • 1. 251.38 --> All are non-zeroes, so 5 sig digs

        2. 1001 --> Two zeroes are between sig digs, so 4 sig digs

        3. 0.00240 --> 2 and 4 are sig., final zero after decimal is sig, other zeroes are only spacing the decimal, so 3 sig digs

• • • Do page 28: 1 in your notes

• Review for quiz

  • • Chapter 1 Review (pages 36-37): 1, 15, 16, 17, 20, 28, 30

    • For the following data, make a scatterplot, fit a line, and find the slope of that line