Date post: | 26-Dec-2015 |
Category: |
Documents |
Upload: | chad-stanley |
View: | 224 times |
Download: | 1 times |
Measurement – A Common Language
The Metric System The metric system is a decimal system
of weights and measures. It is based on the unit of length called
the METER. The metric system is now called, The
International System of Measurement (SI for short).
To get the meter, they divided a line from the north pole to the equator into 10 million parts!
Why do we use Metric System
No numbers to memorize
Easy to say and write
Converts by multiples of 10
Used all around the world
Units of Measurement
Prefixes: Kilo = 1000 Hecto = 100 Deca = 10 (Base Unit)= 1 Deci = .1 Centi = .01 Milli = .001
Examples: Kilometer Hectometer Decameter (Meter) Decimeter Centimeter Millimeter
Length:
The standard unit of length in the metric system is the meter.
Common length units:1 millimeter = 1 mm1 centimeter = 1 cm1 meter = 1 m1 kilometer = 1km
Let’s look at the meter:
1 meter is a little longer than 1 yard or 3 feet.
There are 10 decimeters in 1 meter There are 10 centimeters in 1
decimeter. There are 10 millimeters in 1 centimeterMeasuring length – p. 48
The shell of the turtle in figure 2 is 8.8 cms, how many mms is this?
English to Metric Conversions
39,370 inches = 1 kilometer
3280.8 feet = 1 kilometer
.62 miles = 1 kilometer
1 inch = 2.54 cm
1 foot = 30.48 cm
1 yard = .914 m
1 mile = 1609.3 m
1 mile = 1.609 km
****You do not need to know these.
Let’s Practice
Use the meter stick or the metric ruler to measure the following: careful when choosing what unit to measure in…
1. the length of your lab table2. the length of your science textbook3. the length of your partners hand4. the length of your own pinky finger5. the width of your pinky finger nail6. the width of your pencil point
MassMass is a measure of how much matter an object contains.
The basic unit for mass is kilogram. How many grams = 1 kg?
In the science lab, we will measure in grams.
But…. what is a gram?
The difference between MASS and WEIGHT
Weight = the force of gravity on an object.
Mass = the amount of matter an object contains
120lbs on Earth = 20lbs on the moon
50 kgs on Earth = 50 kgs on the moon
Triple Beam Balance – a device for measuring mass in grams.
Measuring Mass
Let’s learn the parts of the triple beam balance and practice measuring mass. Desktop text p. 49
TIME
The SECOND is the standard SI unit used to measure time.
There are 60 seconds in 1 minute.
There are 60 minutes in 1 hour.
Measuring Volume
Volume - the amount of space an object takes up. **The standard unit for volume is the liter•Volume of liquid = pour liquid into
graduated cylinder and measure amount
•Volume of regular shaped solids = length x width x height in cms (cm3)
•Volume of irregular shaped solids (like a rock)= water displacement.
DENSITY
Density = mass unit = g/cm3 volume = g/ml
p. 52 Let‘s READ.
p.53 Densities of common substances. Once you know an objects density, you can determine whether or not the object will float in a given liquid.
Look at the chart, what is the density of water? Will Aluminum sink or float in water? Explain how you know
What is the density of a pencil with a volume of 4ml, and a mass of 24g?
What is the density of an object with a volume of 12cm3, and a mass of 36g?Let’s find the Mass and Volume of our two
wooden cubes…
The density of water is 1g/cm3 or 1g/ml (1ml = 1cm3)