1cm1cm

1cm

Sand

Meter StickBalance Spring Scale Graduated

CylinderMass/Volume

Thermometer

The Metric System---The Universal Language of Measurement---

• Metric System – scientists & engineers use this language to communicate• The metric system is often referred to as the

International System of Units (abbreviated “SI”)

• The metric system is based on the number 10 and multiples of 10.

LengthThe distance between two points

• Meter – the basic unit of length in the metric system1 meter = 1 m

• Centimeter – one hundredth of a meter1 cm = 1/100 m = 0.01 m100 cm = 1 m

• Millimeter – one thousandth of a meter1 mm = 1/1000 m = 0.001 m = 1/10 cm = 0.1 cm

1000 mm = 1m• Kilometer – one thousand meters

1 km = 1000m1 m = 1/1000 km

• Light year –the distance light travels in one yearSpeed of light = 300,000 km/s

VolumeThe amount of space an object takes up

• Liter – is the basic unit of volume in the metric system1 Liter = 1 L

• Milliliter – is one thousandth of a Liter1 mL = 1/1000 L = 0.001 L

• Milliliters and Liters are used to measure the volume of

• Cubic centimeters – is the metric unit used to measure the volume of

• A cubic centimeter is equal to the volume of a cube that measures 1 cm by 1 cm by 1 cm (cm3).

A volume of a cubic centimeter (cm3) is exactly equal to the volume of one milliliter.

1cm1cm

= 1 cm3 = 1 mL1cm

Massa measure of the amount of matter in an object

• Kilogram – the basic unit of mass in the metric system

1 kg = 1000 grams• Gram – one thousandth of a kilogram

1 g = 1/1000 kg = 0.001 kg1000 g = 1 kg

• Milligram – one thousandth of a gram1 mg = 1/1000 g = 0.001 g1000 mg = 1 g

Weighta measure of the attraction between two objects due to gravity

• Gravity - a force of attraction between two masses.

• The strength of the gravitational force between two objects depends on the masses of the objects and the distance between them:a) The greater the mass, the greater the gravitational

force.b) The greater the distance between the two objects,

the weaker the gravitational force between them• Newton (N) - the basic unit of weight in the

metric system.

Mass vs. Weight

• An object has a universal mass, but may have different weight depending on gravity.

• The mass of an object does not change.• The weight of an object changes as a result of

changes in gravity.• A pineapple on earth weighs more than on the

moon because the earth’s gravity is greater. But the pineapple’s mass always remains the same wherever you go (unless you get hungry and eat it!).

Densitya measure of the amount of matter that occupies a unit certain volume

• Density = mass/volume

(units are usually g/mL)

The density of water = 1.00 g/mL

This means that one gram of water occupies one milliliter of volume.

The density of oil = 0.91 g/mL

If lighter fluids float on heavier fluids, do you expect water to float on oil?

Sand grains

If the human body is nearly 70% water, is it possible to float in quicksand? Should you get worried?

Temperaturea measure of how hot or cold something is

• Celsius = a unit of temperature in the metric system

• Water freezes at 0° C.• Water boils at 100° C.• Normal body temperature is 37° C• Room temperature is 21° C.

Temperature(continued)

• Kelvin = another unit of temperature in the metric system.

• The lowest possible temperature is 0 Kelvin (-273 ° C). This is Absolute Zero.

• To convert from Celsius to Kelvin:

K = C + 273°

Metric Prefixes

Prefix Symbol Meaning

kilo- k 1000 thousand

hecto- h 200 hundred

deka- da 10 ten

deci- d 0.1 tenth

centi- c 0.01 hundredth

milli- m 0.001 thousandth