measurement mr. peterson science center grove middle school north
TRANSCRIPT
MEASUREMENTMr. Peterson
SCIENCE
Center Grove Middle School North
Measurement
Describe the world using numbers Types of Measurement include:
Distance, time, speed, volume, mass…
Measurement can also help describe events
Metric System
Called the International System of Units or SI Decimal system based on 10’s
Prefixes include:Milli (1/1000th)Deci (1/10th)Kilo (1000)
Metric System
Used by scientists all over the world to measure length, volume, mass, weight, density, and temperature.
King Hector Doesn’t Usually Drink Chocolate Milk
KILO HECTO DEKA UNIT DECI CENTI MILLI
Precision and Accuracy
Precision is the closeness of repeated measurements to each other.
Accuracy is the closeness of a measured or derived data value to its true value.precise = repeatable
accurate = true
Practice
Precision and Accuracy
Significant digits are necessary when calculating DON’T COUNT Zeros at the end of the number
without a decimal (ex. 1300) OR Zeros at the beginning of a decimal (ex. 0.0025).
When adding or subtracting, use the smallest number you use.
Example: 4.587
+ 3.1
7.687Answer in significant digits = 7.7
significant digits = 4
significant digits = 2
Precision and Accuracy
Scientific notation is used so large numbers are easier to understand. Move the decimal point until only 1 nonzero
number remains on the left. Count the number of places you moved the decimal and use that number as a power of ten
Examples: 85670000000 = 8.567 x 1010
0.00000045 = 4.5 x 10-7
43289 = 4.3289 x 104
Length
Distance from one point to another METER (M) is the basic unit
1M = 100cm 1M = 1000mm 1km = 1000M
Volume
Amount of space an object takes up Liter (L) is the basic unit of LIQUID volume Cubic centimeter (cm3) is the basic unit of
SOLID volume
Mass
Amount of matter in an object Gram (g) is the basic unit
Weight
Amount of attraction between two objects due to gravity
Newton (N) is the basic unit MASS AND WEIGHT ARE NOT THE SAME!
Density
Mass per unit volume of a substance g/mL is the basic unit Formula: Density = Mass divided by Volume
Density = g/mL Density of water is 1gram/milliliter If an object’s density is less then one it will float. If an object’s density is greater then one it will
sink.
Temperature
Measure of hotness and coldness Celsius (C°) is the basic unit Water freezes at 0° degree Celsius and boils at
100° degrees Celsius.