Chapter 3 Rules and Key Points

1
Chapter 3 Rules and Key Points

• Exponents
• Scientific Notation
• Prefixes
• Metric Conversion
• Velocity
• Weight

2
Exponents

• Rule 3-1 If we make the exponent more positive,
  the decimal point moves to the left.
• Rule 3-2 If the exponent is made more negative,
  the decimal point moves to the right.

• 6700 670 X 10
• 67.0 X 102
• 6.70 X 103
• 0.00275 0.0275 X 10-1
• 0.275 X 10-2
• 2.75 X 10-3

3
Scientific Notation

• Key Point
• Expressing numbers as numbers between 1 and 10
  times the proper power of ten is called
  scientific notation.
• Expressing numbers as numbers times powers of ten
  that are multiples of 3 is called engineering
  notation.

• 47,000 4.70 X 104 in scientific notation to
  three places.
• 47,000 47.0 X 103 in engineering notation to
  three places.

4
Prefixes

• Rule 3-3
• To change numbers with prefixes to regular
  numbers, replace the prefix with the power of ten
  that it represents and then change to a regular
  number.

• 30 mA 30 X 10-3 A
• 0.030 A
• 33 k? 33 X 103 ?
• 33,000 ?

5
Metric Conversion

• Some conversions of linear measure between
  English and metric are
• 1 in 2.54 cm 1 cm 0.3937 in
• 1 yd 0.9144 m 1 m 1.094 yd
• 1 mi 1.609 km 1 km 0.6214 mi

• 20 cm 7.874 in12 in 30.48 cm
• 100 m 109.4 yd
• 5 mi 8.045 km

6
Velocity

• The units of velocity are meters/second or
  kilometers/hour in metric
• feet/second or miles/hour in English.

• 15 m/s 49.22 ft/s

7
Weight

• Common units of weight in metric are the
  milligram, gram, and kilogram.
• In the English system, we have the ounce, pound,
  and ton.

• 16 oz 1 lb 1 kg 35.27 oz
• 2000 lb 1 ton 1 lb 453.6 gm
• 100 lb 45.36 kg
• 100 kg 220.5 lb