Metric Standard Units of Measurement (SI)

The fall of 1999 NASA’s mission to Mars failed due to using English units

instead of metric standard units losing $125,000,000.00 according to

CNN 9/30/99

metric standard units

• Scientist around the world want to work together on investigations.

• To ease this process they have agreed upon certain units for physical measurements.

• These units are the International System or in French “Systeme International”.

• The abbreviation is SI units.

The metric system

• The metric system was developed by French scientists in the 1790’s to create a universal set of units.

• This system is based on the number 10. 1 meter is 10 decimeters.1 second is 1000 or 103 milliseconds1 gram is 0.001 or 10-3 kilograms

List of SI units

Physical Measurement

Name of Unit Unit Abbreviation

length meter m

mass kilogram kg

time second s

temperature Kelvin K

Lab physical measurements

• In a lab we often use the physical measurements of length, mass, volume, temperature, and time.

• The next slide contains a chart of the metric physical measurements we often use in labs.

• Note; due to measuring devices we do not always use SI units.

Lab Units

Physical Measurement

Name of Unit Unit Abbreviation

length centimeter cm

mass gram g

temperature degrees Celsius 0C

time second s

volume liter L