si units. standard s8cs2a. follow correct procedures for use of scientific apparatus. s8cs4b. use...
TRANSCRIPT
SI Units
Standard
S8CS2a. Follow correct procedures for use of scientific apparatus.
S8CS4b. Use appropriate tools and units for measuring objects and/or substances.
Essential Question
What is the importance and purpose of the SI system?
https://www.youtube.com/watch?v=U04nHNUMfPA
https://www.youtube.com/watch?v=KfrCaKyhwZk
The International System
The International System of Units, or SI for short, was designed to provide a worldwide standard of physical measurement for science, industry, and commerce.
SI prefixes:
Prefix Multiplier
giga- 1,000,000,000
mega- 1,000,000
kilo- 1,000
hecto- 100
deka- 10
[unit] 1
deci- 0.1
centi- 0.01
milli- 0.001
micro- 0.000001
nano 0.000000001
Length
Length is defined as the distance between two points. The meter is the SI unit of measure for length
One meter is about the size of a baseball bat
The size of rooms or buildings is often measured with a meter, smaller objects such as a book or pencil is measured with either centimeter or millimeter.
Long distances may be measured with kilometers
How many kilometers is a marathon?
Volume
Volume is the amount of space an object occupies. Volume describes the amount of space inside a 3D object, therefore
the unit is cubed
The cubic meter m3 is the SI unit for volume
To measure the volume of a square or rectangle, measure the length, width, and height and multiply them together.
A liter is a measurement of liquid volume (a 2-liter of soda) 1L=1000 cm3
Mass The mass of an object measures the amount of matter in the
object. This is different from weight***
Kilogram is the SI unit for mass
You can determine mass with a triple beam balance.
Weight
Weight is a measurement of force.
The SI unit for weight is newton (N) What force determines our weight?? Hint- if you travel to other
planets you would weight different amounts depending on the amount of this force present.
Temperature
The physical property of temperature is related to how hot or cold an object is. Temperature is a measure of the kinetic energy, or energy of motion, of the particles that make up matter.
Temperature is measures in SI Units with the kelvin (K) scale
Farenhiet and Celsius temperature scales are the most commonly used scales. These scales DO NOT start at zero (hence both having negative numbers) Kelvin starts at ABSOLUTE ZERO
Time and Rates
Time is the interval between two events The SI unit for time is seconds (s), time is also measured in hours (h)
A rate is the amount of change of one measurement in a given amount of time Speed is a common type of rate measured (kilometers per hour
km/h)
DISCLAIMER
Several units we use everyday are NOT used throughout the rest of the world, and are NEVER used in science. For example: miles, pounds, inches