introduction to physical science. what is science? is a system of knowledge and the methods you use...
TRANSCRIPT
Introduction to Physical Science
What is Science?
• Is a system of knowledge and the methods you use to find that knowledge
• Science begins with curiosity and often ends with discovery
What is Physical Science
• Covers a broad range of study that focuses on non-living things– Two Branches: Chemistry and
Physics
• Chemistry—is the study of the composition, structure, properties and reactions of matter
• Physics—is the study of matter and energy and the interactions between the two through forces and motion
Scientific Method
• An organized plan for gathering, organizing and communicating information
• The goal of any scientific method is to solve a problem or to better understand an observed event
Steps in the Scientific Method
1. Problem/Question what you want to know
2. Research gather information about the question
3. Hypothesis is a proposed answer to the question or educated guess
Steps in the Scientific Method
4. Perform an Experiment test the hypothesis
5. Analysis of Data
6. Conclusion
Parts of an Experiment
• Trial repeating the experiment
• Variable any factor that can change in an experiement– Independent/
Manipulated factor you change
– Dependent/Responding factor that changes as a result of the independent/manipulated variable
Parts of an Experiment
• Constant factors that does not change
• Controlled experiment is an experiment in which one variable is deliberately changed at a time
Theory verse Law
Theory LawA well-tested explanation for set of observations
not widely accepted
Can be proven wrong
Is a statement that summarizes a pattern found in nature
widely accepted
99% true
Measurement
• SI UNITS– SI = Standard
International– By adhering to one
system of units, scientists can readily interpret one another’s measurements
Measurement—Length
• The straight line distance between two points
• SI unit: meter (m)
• Tools: meter stick or ruler
Measurement—Mass
• How much matter is in an object
• SI Unit: kilogram (kg)
• Tools: balances, electric scales, spring scales
Measurement—Temperature
• Amount of heat given off by an object
• SI unit: Kelvin (K)
• Tool: thermometer
Measurement—Volume • Amount of space an
object takes up• Volume of a liquid
– Use a graduated cylinder
– Unit: liter (L)
• Volume of Regular Object (a block)– Use a ruler (LxWxH)– Unit: cubic centimeters
(cm3)
Measurement—Volume
• Volume of Irregular Solid (a rock)– Use water
displacement: the difference in water level when something is placed in a graduated cylinder
– Unit: liter (L)
Density• Density = mass / volume
• Units: g/mL or g/cm3
• Density of Water = 1g/mL
• Any object’s density greater than water will sink
• Any object’s density less than water will float
Density Practice
1. What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3?
2. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? Would the piece of wood float in water?
Density Problems
3. The density of aluminum is 2.70 g/mL. If the mass of a piece of aluminum is 244 grams, what is the volume of the aluminum?
4. An ice cube measuring 5.80 cm by 5.80 cm by 5.80 cm has a density of 0.917 g/mL. What is the mass?
Conversions within The Metric System
King Henry Died By Drinking Chocolate Milk
• Kilo—King—k--1,000 • Hecto—Henry—H—100 • Deka—Died—dK—10 • Base—By--m,L,g • Deci—Drinking—d--0.1 • Centi—Chocolate—c--0.01 • Milli—Milk—m--0.001
Practice
1. 7.09 g to _________ kg
2. 5.0 mL to ________ L
3. 3.2 km to ________ mm
4. 0.054 L to ________ mL
5. 67.5 kg to ________ g
Data
• Information gathered from experiments
• Qualitative– Data in forms of words– Usually observations– Ex: The floor is made of tile
• Quantitative– Data in forms of numbers– Ex: Jim jumps 5 meters in the
air
Graphs Parts
• X-axis– Horizontal Axis– Independent/
Manipulated variable– Cause
• Y-axis– Vertical Axis– Dependent/
Responding variable– Effect
Types of Graphs
• Line Graph– Useful for showing changes that
occur in related variable (ex: time)
– Direct proportion—as one variable increase the other variable increases as well
– Inverse proportion—as one variable increase the other variable decrease
– Constant graph—as one variable increases the other variable stays the same
Types of Graphs
• Bar Graph– Often used to compare
a set of measurements, amounts or changes
• Circle Graph– Is a divided circle that
shows how a part or share of something relates to the whole