1. Scientific Method, Measurements and the Metric System
Methods of Science
Scientific Method, Measurements and the Metric System

2. What is Science? Science
Process that uses observation and investigation
Used to gain knowledge about events around us
Latin word scientia = knowledge

3. Major Categories of Science
Life Science
Living things
Earth Science
Investigates Earth & space
Physical Science
Matter and energy

4. Scientific Method Scientific Method
Organized set of investigation procedures
6 steps
Some steps repeated or skipped during an investigation

5. Scientific Method Observe a problem Gather info Hypothesis Experiment
Possible explanation
Experiment
Test
Analyze data
Draw conclusion
REPEAT !!!!

6. Variables in an Experiment
Must be in a controlled environment
Usually consists of two variables
Variable = quantity that can have more than one value

7. Dependent vs. Independent
Independent variable
Variable in the experiment you change
What is being tested
Dependent variable
Value changes according to the independent
“depends” on the independent
What you are measuring

8. Constant and Controls Constant Variables Control Group
Factors in the experiment that does not change
Allows for a “fair” test
Control Group
Standard by which results can be compared

9. For Example:
Students of different ages were given the same jigsaw puzzle to put together. They were timed to see how long it took to finish the puzzle.
Independent = ??? (What is being tested; changed?)
Dependent = ??? (What are you measuring?)
Controlled = ??? (What variable stayed the same?)

10. For Example:
Students set up an experiment to determine which of three fertilizers helps plants grow taller.
Independent?
Dependent?
Control Variables?

11. Independent vs. Dependent
Extra Practice
Identifying Independent vs Dependent Variables

12. Standards of Measurement
Exact quantity used to compare measurements
U.S. uses English system standards & metric standards
Most other nations all metric system
Metric & Standard Measurement Systems
English Vs. Metric System
Yards vs. Meters
Gallons vs. Liters
Pounds vs. Grams
Miles vs. Kilometers
Fahrenheit vs. Celsius

13. Metric System SI System System International Aka metric system
Accepted by scientist throughout the world
Uses a base unit with prefixes
Based on units of 10
Why science uses the metric system.

14. Metric System Base Units
Meter measures length
Liters measures volume
Gram measures mass
Second measures time
Celsius/Kelvin measures temp

15. Metric Prefixes Metric Prefixes Use prefixes with base units
Kilo = 1000
Hecto = 100
Deca = 10
Base Units (g, L & m) = 1
Deci = 1/10
Centi = 1/100
Milli = 1/1000
Metric System Rap

16. Metric Prefixes

17. Length Length Distance between two points
Metric base unit is the meter
Use metric prefixes according to what you’re measuring
Use ruler, meter stick or tape measure to find lengths of objects

18. Volume Volume Amount of space occupied by an object
Volume of a liquid is measured with base unit Liter
Volume of a solid is measured with unit of length
Length x Width X Height
L(1) x L(2) x L(3)
Unit of length³

19. Volume Volume of a liquid Volume of a solid
Use graduated cylinders for precise volume
Beakers for accurate volume
Volume of a solid
Use ruler or meter stick to measure 3 dimensions

20. Volume
Volume Equivalencies
1 cm³ = 1 mL = 1g
1,000 cm³ = 1 L

21. Mass Mass Amount of matter in an object Metric base unit is the gram
Use triple beam balance or electronic balance when measuring mass

22. Density Density The mass per unit volume of an object
Density equals mass of an object divided by the volume
D = m/v
Unit for density is g/cm³ OR g/mL
Density < 1 object floats
Density > 1 object sinks

23. Time and Temperature Time Temperature Interval between two events
Unit of measurement is seconds
Temperature
How hot or cold something is
Unit of measurement is °Celsius or °Kelvin

24. Temperature Conversions
Temp Conversions
Water boils at 100° C and 212° F
Water freezes at 0° C and 32°F
C = (F – 32) x .56
F = (C x 1.8)

25. Example Problems
Find the volume of a box that has a length of 2.3 mm, height of 3.4 mm and a width of 2.1 mm.
2. Find the width of a container that has a volume of 120 cm³, length of 10 cm and height of 5 cm.
3. Find the density of an object that has a mass of 2.1 mg and volume of 9.2 mm³.
4. Find the mass of an object that has a density of 0.78 g/ml and a volume of 16 ml.

26. Example Problems 1. Convert the following: 97° F to C 12°F to C
45° C to F
97° F to C
12°F to C
65° C to F