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Units & Measurements. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29. Measurements. This is a result of determining the ratio of a physical quantity to a unit of measurement. You are doing measurements when you: read your watch
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Measurements This is a result of determining the ratio of a physical quantity to a unit of measurement. • You are doing measurements when you: • read your watch • check your weight • take your temperature ONE MUST SET A STANDARD!
Physical Quantities - any number that is used to describe a physical phenomenon • Fundamental Quantities: • Length • Mass • Time • Temperature • Electric Current • Luminosity • Amount of Substance • Derived Quantities: • combination of fundamental units • Ex. • Area = (Length x Length) • Volume = (Length x Length x Length) • Speed = (Length / Time ) • Force = (Mass x Acceleration)
Standards of Measurement • Gaussian Units • Length = centimeter • Mass = grams • Time = seconds • English Units • Length = foot • Mass = slugs • Time = seconds • SytemeInternationale (SI) • Length = meter • Mass = kilograms • Time = seconds
Unit Prefixes Subdivisions and multiples of SI units are widely used. Each is designated by a prefix according to the corresponding power of ten. Home Work #1 Research about Unit Prefixes from x10-18to x1018 . Follow the format below. Ex.
Unit Conversion Mass 1 kg = 1000 g 1 gram = 1000 milligrams 1 slug = 14.59 kg Length 1 km = 1000 m 1 meter = 100 cm 1 cm = 10 mm 1 ft = 12 in 1 inch = 2.540 cm 1 mile = 1.609 km Time 1 hour = 60 min 1 min = 60 s 1 day = 24 hours
Significant Figures • Identify the # of sf. • 0.600700 L • 40.0 g • 560.08 m
Operations Involving SF Addition or Subtraction 23.1 g 37.504 g 60.604 g 5.438 mL 0.21 mL 5.228 mL + - Final Answer: 60.6 g Final Answer: 5.23 mL
Operations Involving SF Multiplication or Division 9.1 m 0.05 m 0.4605 m2 10.75 cm 3.2 3.359375 cm x ÷ Final Answer: 0.5 m2 Final Answer: 3.4 cm
Scientific Notation -used when measurements involve very small and very large numbers - a method of writing numbers in terms of decimal number between 1 and 10 (N) multiplied by a power (n) of 10 N x 10n Example: 0.00000328 m = 3.28 x 10-6 m 953 000 L = 9.53 x 105 L
Seatwork #3 Write in scientific notation. • 24327 • 0.0000000056 • 46600000 • 32000000 • 0.000467 Express the following as an ordinary number. • 5.43 x 10-3 • 4.4 x 10-4 • 3.0 x 108 • 6.12 x 105 • 1.4 x 109
For Scientific Notation Addition or Subtraction 8.2 x 102 mm 5.0 x 102 mm 13.2 x 102 mm 9.11 x 103 µg 3.6 x 102 µg 9.11 x 103 µg 0.36 x 103 µg 9.47 x 103 µg + + + 9.5 x 103 µg
For Scientific Notation Multiplication or Division Final Answer: 3.6 x 10 7 m2 9.0 x 103 m 4.0 x 103 m 3.5 x 10-4 km 1.0 x 103 km 36 x 106 m2 × × Final Answer: 3.5 x 10 -1 km2 (3.5 x 1.0) x 10(-4+3) km2 3.5 x 10-1 km2
Home Work #2 6. (6.4 x 106)/(8.9 x 102) 1. (4.215 x 10-2) + (3.2 x 10-4) 7. 4503 + 34.90 + 550 2. (3.4 x 106)(4.2 x 103) 8. (3.2 x 103)/(5.7 x 10-2) 3. (6.73 x 10-5)(2.91 x 102) 9. 1.0236 – 0.97268 4. (8.97 x 104) - (2.62 x 103) 10. 2.8723 x 1.6 5. (6305)/(0.010) 11. 1.23 + 2.02
II. Carry out the following operations using correct number of SF • 41.5 cc + 21.000 cc • 6.30 L + 0.0008 L • (9.1 x 108 m) - (2.5 x 105 m) • (0.82 km) (12.0 km) • 10.9 cm3 ÷ 0.5 • (4.8 x 10-7m) (7.0 x 10-2 m)