SI Measurement

• Le System international d’Unites

• Internationally agreed – 75 000 not 75, 000– Meters not miles– Liters not gallons

Units?

• mass

• length

• Volume

• Time

• Amount of a substance

Other Units

• Derived unit – combination of units like in velocity m/s2, or pressure kg/m s2

• Density – g/cm

Density

• D = m/v

• Ratio of mass to volume

• The mass divided by the volume

• Physical property

Mass

• kilogram is the standard– 1000 grams

• We use grams – more useful in science class.• King Henry Chart

– Remember

• Mass measure of matter, does not depend on gravity

• Weight – measure of the gravitational pull on the mass

Mass and weight

• mass is the amount of matter and will not change with location

• Weight is a measure of gravity and will change with location

How to convert

• King Henry chart – memorize

• King Henry drank uho delicious chocolate milk

• Kilo Hecto daka ______deci centi milli

Larger prefixes

• Mega

• Giga

• tera

Smaller prefixes

• Micro

• Nano

• Pico

• Femto

• atto

Multiple conversions

• Affects density, area etc

• If the unit is squared, you need to convert twice.

• If the unit is cubed you need to convert _______________

Practice

• Pg 60. #31-34