The metric system - SI

The system of measurement in science

Lecture Notes

Meter, Liter, Kilogram

Length- the distance between two points; the Meter is the base unit for length

Volume- amount of space something occupies; the Liter is the unit for volume of liquids

Mass- the amount of material something has in it; the Kilogram(Kg), is the base unit for measuring mass

Making base units larger or smaller

Prefix Abbrev. MeaningK ilo- K 1,000hecto- h 100deka- da 10deci- d .1 (1/10)

centi- c .01(1/100)

milli- m .001(1/1000)

Measuring

Length is measured by• metersticks or metric rulers

Volume is measured by• liquid volume by a graduated cylinder-

always read from the bottom of the meniscus

Mass is measured by• triple-beam balance or digital balance

Derived Units

Area- the amount of surface within a set of boundaries• Length X Width= Area• Possible units cm2

Volume- the space an object occupies• Length X Width X

Height= Volume• Possible units cm3

Density- the amount of matter in a unit volume of any substance• Mass / Volume= Density• Possible units g/cm3

Weight vs. Mass

Weight- a measure of the gravitational force exerted on an object by another body• SI unit for

gravitational force is newtons

Mass of an object is the same no matter where it is measured in the universe

Time and Temperature

Time- measurement of the span between two events• The SI unit for time is

the second

Temperature- a measure of the average kinetic energy of all particles within an object• Measured with a

thermometer• Scientist often use the

Celsius scale• The SI unit is Kelvin• Degree Celsius +

273= Kelvin