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1 Introduction. Theories & Laws Math Review Measurements & Units Significant Figures Problem Solving Vectors General Properties of Vectors Hk: 1, 5, 23, 35, 53. Theories & Laws. Theories explain phenomena Laws are statements Laws usually come first.
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1 Introduction • Theories & Laws • Math Review • Measurements & Units • Significant Figures • Problem Solving • Vectors • General Properties of Vectors • Hk: 1, 5, 23, 35, 53.
Theories & Laws Theories explain phenomena Laws are statements Laws usually come first. Example: Boyle’s Law; P ~ 1/V (1662) Bernoulli’s Kinetic Theory of gases (1740). 2
Math Review • Percentages (Giam 01 9) • Proportions (Giam 01 11+) • Graphs & slopes • Derivatives & Integrals (polynomial)
Measurement & Units • Units describe and clarify (Giam 01 21) • SI units include meter, kg, and second • Combinations of these units are called Derived Units, e.g. speed = m/s, acceleration = m/s/s, force = kg·m/s/s • Brackets used to indicate units of a variable, e.g. [v] = m/s • /
Unit Analysis calculation and comparison of units Given: v = at, [v] = m/s, [t] = s, what are the value of [a]? [v] = [a][t] m/s = [a]s [a] = m/s/s 5
Dimensional Analysis units replaced by “dimensions” e.g. meter = L, seconds = T unit-independent e.g. [velocity] = L/T / 6
Prefixes for SI Units • convenient shorthand for powers of 10 • examples: • m = 10-3 e.g. millimeter • c = 10-2 e.g. centimeter • k = 103 e.g. kilometer
Significant Figures (s.f.) • trailing 0’s count, e.g. 1.560 • leading 0’s not counted, e.g. 0.01 • more s.f. implies more precision
Problem Solving • write key data as you read • mark unknowns with “?” • double check each value • use SI values, e.g. meter, kg, s • draw physical situation • write equations • solve, consider, read question again
Vectors Magnitude & Direction Magnitude || (g4-5) Notation, Example Component Example Animated Phet Vectors 12
Example Vector Addition 0 R = (10cm, 0°) + (10cm, 45°): 15
0 (cont) Magnitude, Angle: 16
0 General Properties of Vectors • size and direction define a vector • location independent • change size and/or direction when multiplied by a constant • written: Bold or Arrow
Summary • Theories explain. Laws describe. • Math Review • SI units & analysis • Significant Figures • Problem Solving Strategy • Vector = magnitude + direction • /
0 Common Metric Prefixes
0 these vectors are all the same
A 0.5A -A -1.2A Multiplication by Constants 0