Post on 06-Mar-2018
transcript
Units of Measurement
1-2
►SI Units and symbols
►Length
distance between two (2) points
►SI unit meter (m)
100cm = 10dm = 1m
*the unit used depends on size of the item being measured*
►Pencil = cm
►Classroom = m
►Long Distances = km (1000 meters)
►1km = about 10 football fields long
►Convert = Change
►Rules of conversion
A measurement consists of two (2) points:
► Number AND Unit label
To convert from LARGER to SMALLER units- Multiply
To convert from SMALLER to LARGER units Divide
(Use step chart)
►METER STICK = ►10 dm =100 cm =1000 mm
1 km = 1000m
Volume
►amount of space occupied by an object ►V = L x W x H
(cm3) (m3)
Derived Units
Units obtained by combining SI Units
Converting M to cm p40
►How many cm are in 1.98 meters?
What is known?
►1m = 100cm
►Larger to smaller = multiply
►1.98 X 100 = 198
►198 cm
Practice Problem How many centimeters are in 253.8 km? HINT: Change km to m; then m to cm. 253.8km = 25,380,000cm
Practice problem 2 A bookshelf is 75 cm wide. How many decimeters is this? How many meters? 75 cm = 7.5 dm 75 cm = 0.75 m
Volume of liquid:
►container that holds the amount of liquid Liters
Milliliters ►(medicine = cm3)
1L = same volume as a cubic decimeter (dm3) ►1dm = 10 cm
►1L = 1000mL
►1dm3 = 1000 cm3
►1L = 1dm3
►1mL = 1cm3
►1L = 1000cm3
►MASS =
Measurement of the matter in an object use a balance
► SI Unit of mass = kg ►Small objects = mass = grams (g) or mg
► 1kg = 1000g
►Density = mass per unit of volume of material ►D = m/v
►Time and Temp
Time = interval between 2 events (second)
stopwatch/clock
► Temp = how hot or cold something is thermometer – Celsius scale
► Freezing = 0 deg C
► Boiling = 100 deg C
► Human = 37deg C
► Room temp = 20 – 25 deg C
► SI units of temp = Kelvin (K)
► 0K = Zero on the Kelvin Scale Absolute zero (coldest possible temp (-273 deg C)
(273 degrees below the freezing point of water) ► Kelvin temp add 273 to Celsius
► Water freezes at 273 deg K
► Boils at 373 deg K
►Graphs
Graph: Visual display of information
Line Graph: Show trends or how data changes
Bar Graph: Comparing info
Circle Graph: Show a fixed quantity broken into pieces