8/24/10

Post date: Aug 24, 2010 12:1:4 AM

Bell Ringer: What is scientific notation? What do we use it for?

    • Scientific notation

      • Used to express very large or very small numbers

      • General format is M x 10^n

        • M is the non-zero numbers at the left side of a very large or small number. M is always a number with only one digit to the left of the decimal

        • n tells us how far to move the decimal place (positive means right, negative means left)

        • e.g. 4.5 x 10^3 is the same as 4500 (decimal in 4.5 was moved to the right 3 places)

        • e.g. 6.8 x 10^-3 is the same as 0.0068 (decimal in 6.8 was moved to the left 3 places)

      • Read "Scientific Notation" on pages 15-16

      • Do Page 16: 1-3 (due Wednesday), but don't turn in yet because we'll add to it

    • Prefixes

      • Each prefix has a "multiplier" associated with it. In order to change a unit with a prefix to the base unit, simply replace the prefix with the multiplier

        • e.g. the multiplier for kilo is 10^3, so 143 kilometers is the same as 143 x 10^3 meters.

        • Add Page 17: 4-5 to the previous 3 problems.

  • The factor-label method for changing units

      • See page 10 of your lab manual

      • Effectively, we multiply a measurement by a carefully chosen form of "1" to change the units without changing the value of the measurement.

      • e.g. 25.4 cm ---> inches

        • 25.4 cm x (1 inch / 2.54 cm) = 10 inches

  • Factor-label practice