Scientific Measurements:

Objectives:

1.    Compare the different units of measurement in the metric system.

2.    Explain how to measure distance, volume, mass, & temperature in standard metric measurements.

3.    Demonstrate how to measure the metric units distance, volume, mass, & temperature.

Key Terms:

Web Resources:

Notes:

Throughout the different scientific disciplines you will find the use of the metric system.  Becoming familiar with the standard prefixes will make solving equations and converting units easier.

 Prefix Symbol Meaning Scientific Notation exa- E 1,000,000,000,000,000,000 1018 peta- P 1,000,000,000,000,000 1015 tera- T 1,000,000,000,000 1012 giga- G 1,000,000,000 109 mega- M 1,000,000 106 kilo- k 1,000 103 hecto- h 100 102 deka- da 10 101 meter 1 100 deci- d 0.1 10-1 centi- c 0.01 10-2 milli- m 0.001 10-3 micro- m 0.000001 10-6 nano- n 0.000000001 10-9 pico- p 0.000000000001 10-12 femto- f 0.000000000000001 10-15 atto- a 0.000000000000000001 10-18

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 Distance Mass Volume Pressure / Energy Temperature 1km = 0.62 mi 1kg = 2.2lbs 3.744L = 1 gal 101,325Pa = 1atm oC = 5/9 (oF-32) 1m = 39.37in 907.185kg = 1ton 1 L = 1.06qt 4.184J = 1cal oK = oC + 273 1m = 1.0963yd 28.3g = 1oz 250ml = 1c 1cm = 0.39370in 453.59g = 1lb

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The units used in science are those primarily used throughout the world.  The International System of Units (SI) is a system based on the metric system.  There are 7 fundamental units of measure.

 Name Symbol Unit of Measure Unit Symbol Unit Dimensions length (distance) l (d) meter m m mass m kilogram kg kg time t second s s electric charge Q coulomb C C temperature T Kelvin K K amount of a substance n mole mol mol luminosity intensity l candela cd cd

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All other SI units can be derived from the above 7.

 Name Symbol Unit of Measure Unit Symbol Unit Dimensions acceleration a meter per second squared m/s2 m/s2 area A square meter m2 m2 capacitance C Farad F C2*s2/kg*m2 density D kilogram per cubic meter kg/m3 kg/m3 electric current I Ampere A C/s electric field intensity E Newton per coulomb N/C kg*m/C*s2 electric resistance R Ohm d kg*m2/C2*s emf x Volt V kg*m2/C*s2 energy E Joule J kg*m2/s2 force F Newton N kg*m/s2 frequency f hertz Hz s-1 heat Q Joule J kg*m2/s2 illuminance E lumens per square meter lx cd/m2 inductance L Henry H kg*m2/C2 luminous flux F lumen lm cd magnetic flux f Weber Wb kg*m2/C*s magnetic flux density B Tesla (weber per square meter) T kg/C*s potential difference V Volt V kg*m2/C*s2 power P Watt W kg*m2/s3 pressure p Pascal (Newton per square meter) Pa kg/m*s2 velocity v meters per second m/s m/s volume V cubic meter m3 m3 work W Joule J kg*m2/s2

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 Speed of light in a vacuum 2.9979 x 108 m/s Speed of sound 330 - 350 m/s (depending on temperature) Acceleration due to Gravity 9.8 m/s2 Average Earth - Sun distance (1 AU) 1.50 x 1011 m Average Earth - moon distance 3.84 x 108 m Average radius of the Sun 6.96 x 108 m Average radius of Jupiter 6.99 x 107 m Average radius of Earth 6.37 x 106 m Average radius of the moon 1.74 x 106 m Average radius of the hydrogen atom ~5 x 10-11 m Mass of the Sun 1.99 x 1030 kg Mass of Jupiter 1.90 x 1027 kg Mass of Earth 5.98 x 1024 kg Mass of the moon 7.35 x 1022 kg Proton mass 1.6726 x 10-27 kg Neutron mass 1.6749 x 10-27 kg Electron mass 9.11 x 10-31 kg Atomic mass unit (amu) 1.66054 x 10-27 kg Electron charge 1.6 x 10-19 C Avogadro's number 6.02 x 1023 Planck's constant (h) 6.6262 x 10-34 J-s Gas constant (R) 0.08206 atm-L/mol-K Molar volume of gas 22.4L

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