Physics Topic 1
Measurements and Mathematics
• Physics
• Measurements and Mathematics
• Obj: SWBAT perform unit conversions and
assign the number of significant digits to a
measurement
• Do Now: What are some concerns you have
for physics?
• Physics
• Measurements and Mathematics
• Obj: SWBAT perform unit conversions and
assign the number of significant digits to a
measurement
• Do Now: How many cm are in 3.4 m?
COPY THESE
SI Units
SI Prefixes
Conversions
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1 Tera gram = 1,000,000,000,000 grams
1 Giga gram = 1,000,000,000 grams
1 Mega gram = 1,000,000 grams
1 kilogram = 1,000 grams
1 gram = 100 centi grams
1 gram = 1,000 milli grams
1 gram = 1,000,000 micro grams
1 gram = 1,000,000,000 nano grams
1 gram = 1,000,000,000,000 pico grams
Dimensional Analysis (a fancy name for
changing units)
Tools for Measurement
• Length
• Force
• Mass
• Time
• Angle
Making Measurements
AND
ONE MORE UNIT!!!
• Read what the instrument says
Trigonometry
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Sin A
Sin C
Cos A
Cos C
Tan A
Tan C
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20/29
21/29
21/29
20/29
20/21
21/20
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Sin A
Sin C
Cos A
Cos C
Tan A
Tan C
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40/50
30/50
30/50
40/50
40/30
30/40
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Sin A
Sin C
Cos A
Cos C
Tan A
Tan C
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36/39
15/39
15/39
36/39
36/15
15/36
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Sin A
Sin C
Cos A
Cos C
Tan A
Tan C
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8/17
15/17
15/17
8/17
8/15
15/8
Uncertainty in Measurement
• Precise – when data points are close to each
other
• Accuracy – when data points are close to the
correct value
• Physics
• Measurements and Mathematics
• Obj: SWBAT perform unit conversions and
assign the number of significant digits to a
measurement
• Do Now: How many SigFigs are in 3.400 m?
Significant Figures / Digits (Sig Figs)
• Rules for counting
1.
2.
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4.
All non-zero numbers count
Zeros before a non-zero digit don’t count
Zeros in-between non-zero digits count
Zeros after non-zero digit only count if there’s a
decimal point
How many significant figures are
represented in each of the following
numbers?
Adding and Subtracting
• Answer has the fewest number of
decimal places
Multiplication and Division
• Answer has the fewest number of
Significant Digits
Scientific Notation
• Only count the coefficient for Significant Digits
Math with Scientific Notation
• Add/Subtract 🡪 power of 10 must be the
same
• Multiplication/Division
Rewrite the following numbers in
scientific notation
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4020
13796
0.015
0.0000007
1.80
1 trillion
430,000,000,000,000,000
Graphs
• Independent variable – what the
experimenter changes (x-axis)
• Dependent variable – what the experiment
measures (y-axis)
Direct
Proportions
Direct Squared
Inverse
Constant
Indirect Squared
Scalars and Vectors
• Scalar – quantity with magnitude only
• Vector – quantity with magnitude and
direction