Chapter 1
Hints on Problem Solving
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First |
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Make a sketch |
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Mark on it what you want to know |
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Identify what you are trying to
determine |
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This will help you organize your
thoughts |
Hints on Problem Solving
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Second |
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Identify principles involved in the
problem |
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Look for relationships that connect
unknown and known quantities |
Hints on Problem Solving
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Third |
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Decide which equations should be used |
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Substitute known information into
selected equations and solve for unknown quantity |
Hints on Problem Solving
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Fourth |
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Check answer by substituting it into
original equation |
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Ask yourself, “Does the answer seem
reasonable?” |
Hints on Problem Solving
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Finally |
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Is it in the “right ballpark”? |
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Are units on both sides of the
equations correct? |
SI System of Units
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Length |
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Meter (m) |
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Mass |
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Kilogram (kg) |
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Time |
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Second (s) |
SI System of Units
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Electric Current |
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Ampere (A) |
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Temperature |
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Kelvin (K) |
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Amount of a substance |
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Mole (mol) |
Relative Size of the
Units
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1 meter is about 1 yard |
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1 inch is about 2½ centimeters |
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1 newton is about the force required to
lift a ½-pound weight |
Relative Size of the
Units
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Raising a ½-pound weight 1 meter in 1 s
requires about 1 watt |
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Room temperature is about 35 degrees
Celsius or about 300 degrees kelvin |
Converting Units
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Convert 60 miles/hour to km/hr |
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Convert 60 miles/hour to m/s |
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A circle has radius of 6 inches |
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Determine the area in square meters |
Power of Ten Notation
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For very large and very small numbers |
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35 000 = 3.5 × 104 or 35 ×
103 |
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458 000 = 4.58 × 105 or 458 ×
103 |
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0.000 042 = 4.2 × 10-5 or 42
× 10-6 |
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0.000 159 = 1.59 x 10-4 or
159 x 10-6 |
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Powers of Ten
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To multiply numbers in power of 10
notation |
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Multiply their base numbers |
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Add their exponents (e.g., 103
x 105 = 108) |
Powers of Ten
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To divide numbers in power of 10
notation |
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Divide their base numbers |
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Subtract their exponents (top - bottom)
(e.g.,109/103 = 106) |
Power of Ten Notation
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To add or subtract, adjust all numbers
to same power of ten |
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It does not matter what exponent you
choose, as long as they are all the same |
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Power of Ten Notation
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For example |
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3 x 104 + 5 x 103
= 35 x 103 (changing both powers of 10 to 3) |
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Or |
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3 x 104 + 5 x 103
= 3.5 x 104 (changing both powers of 10 to 4) |
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Power of Ten Notation
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Raising a number to a power is a form
of multiplication |
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(4 × 103)2 = (4
× 103)(4 × 103) |
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= 16 × 106 |
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Fractional powers represent roots |
Prefixes
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Scientific Notation |
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24 700 = 2.47 × 104 |
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0.000 046 = 4.6 × 10-5 |
Prefixes
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Engineering Notation |
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Uses only powers that are factors of 3 |
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24 700 = 24.7 × 103 |
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0.000 046 = 46 × 10-6 |
Prefixes
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Metric Prefixes are used for
convenience |
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Significant Digits and
Numerical Accuracy
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Significant digits |
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Digits that carry information |
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It is a common error to show more
digits of accuracy than are warranted |
Significant Digits and
Numerical Accuracy
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Number of significant digits in a
result due to multiplication or division is the same as the number of
significant digits in the number with the least number of significant digits. |
Circuit Diagrams
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Electric circuits |
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Use batteries and resistors as
components |
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Circuit diagrams are used on paper |
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Three types are used |
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Pictorial, block, and schematic |
Pictorial Diagrams
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Help visualize circuits by showing
components as they actually appear |
Block Diagrams
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Blocks represent portions of a system |
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Schematic Diagrams
Aids to Circuit Analysis
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Prepackaged Simulation Software |
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PSPICE, Electronics Workbench |
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Math Software |
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MathCAD, MATLAB |
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Programming Languages |
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BASIC, C, C++, FORTRAN, Assembly |
Aids to Circuit Analysis
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Graphing Programs |
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PSI Plot |
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Axium |
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Electronic Calculators |
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TI-86 |
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TI-89 |