Transcript Chapter 1

Chapter 1
Science Skills
Page 2
1.1 What is science?
(3:54)
Science From Curiosity
• Science - system of knowledge & methods
used to find it
• Begins w/ curiosity…ends w/ discovery
• Curiosity provides ?’s
• Observing/measuring…means to find
answers
Science and Technology
Science and Technology (1:39)
• Science / technology interdependent
– Advances in 1 leads to advances in the other
Branches of Science
Natural Science
Physical Science
•Chemistry
•Physics
Earth and Space
Science
•Geology
•Astronomy
•Life Science
•Biology
Big Ideas of Physical Science
• Space and Time
– universe age
– size
• Matter and Change
– Small amt for universe
– Volume/mass
– Atoms
• Protons, neutrons, electrons
• Forces and Motion
– Push/pull causes change
– Laws will explain
• Energy
– Many forms
– Drives motion
– Transferred/never destroyed
Sec 1.2 Using a Scientific Approach
p. 7
• What is the Scientific Method?
– organized plan scientists use to answer ?’s
about natural world.
– only scientific way accepted to back up idea.
– used to support /disprove theory
Step 1: Ask a Question
• Develop ? to solve
thru experimentation
• make observations
• Ask ? about ur
observations
Step 2: Form a Hypothesis
• Educated guess
– previous experience/
research
• Possible answer to ?
• TESTABLE!
Step 3: Conduct Experiment
• Develop / follow
procedure
• detailed materials list
• so detailed that anyone
who disputes ur work
can reproduce exactly
• outcome measurable
(quantifiable)
Variables – “to vary or change”
 Independent Variables - part of
experiment you change
 Dependent Variables - part that changes
(or not) as result of changes u made
 Control
Group - ur basis for comparison
 Constants - parts of exp that don’t change
Step 4: Analyze the Results
• Record data during experiment to keep
track of what’s happening
• Data tables, graphs, or photos
Step 5: Draw Conclusions
• examine data
• 2 possible outcomes:
–experiment supported hypothesis regarded as true
–experiment disproved hypothesis
• If hypothesis rejected, ask ?’s:
–poor observations?
–Poor/inaccurate measurements?
–Flawed experiment?
I haven’t failed, I’ve found 10,000
ways that don’t work (Thomas
Edison)
Scientific Method Rap
Mr. Duey
Theories v.s. Laws
Theory
Law
Explains
observations /
experimental
results
summarizes
pattern found in
nature
Answers “why”
Answers “what”
DOESN’T explain
observed pattern
in nature
Never proven –
strengthened or
revised/replaced
Scientific Models
• Scientific Models - makes easier to
understand things too hard to observe
directly
– Ex. Atomic models, models of the solar
system, cell models, etc.
The Scientific Method (12:07)
Section 3
Measurements
p. 14
Using Scientific
Notation
 Written as # btwn 1 &
10 and a power of 10
 Makes very large/small
#’s easier to work w/
The Distance From the Sun to the
Earth
93,000,000 miles
Step 1
• Move decimal left
• Leave only 1 # in front of
decimal
Step 2
• Write the # w/o zeros
Step 3
• Count # places decimal
moved
• That’s power of ten
Standard Form
Scientific Notation
Practice Problem
Write in scientific notation.
Decide the power of ten.
1)
2)
3)
4)
98,500,000 = 9.85 x 10?
64,100,000,000 = 6.41 x 10?
0.0000000279 = 2.79 x 10?
0.00042 = 4.2 x 10?
9.85 x 107
6.41 x 1010
2.79 x 10-8
4.2 x 10-4
Complete Practice Problems
Write in scientific notation.
4
10
5x
1) 50,000
6
7.2
x
10
2) 7,200,000
3) 802,000,000,000 8.02 x 1011
Multiplying numbers in scientific
notation
• When x #s in sci not, its 2 steps:
A rectangular parking lot has a
3
length of 1.1 x 10 meters and
width of 2.4 x 103 meters. What
is the area of the parking lot?
Step 1
• X base #s
1.1 x 2.4 =
2.6
Step 2
• add exponents 3 + 3=
1.1 x
3
10
m x 2.4 x
2.6 x
6
10
3
10
2
m
6
m=
DID YOU KNOW
It’s a metric world
The United States is the only western country not
presently using the metric system as its primary
system of measurement. The only other countries in
the world not using metric system as their primary
system of measurement are Yemen, Brunei, and a few
small islands.
DID YOU KNOW
In 1906, there was a major effort to convert to the
metric system in the United States, but it was
opposed by big business and the attempt failed.
The Trade Act of 1988 and other legislation declare
the metric system the preferred system of weights
and measures of the U.S. trade and commerce, call
for the federal government to adopt metric
specifications, and mandate the Commerce
Department to oversee the program. The conversion
is currently under way; however, the metric system
has not become the system of choice for most
Americans’ daily use.
Lost in space
In September 1999, the United
States lost the Mars Climate Orbiter
as it approached Mars. The loss of
the $125 million spacecraft was due
to scientists confusing English units
and metric units.
DID YOU KNOW
Two spacecraft teams, one at
NASA’s Jet Propulsion Lab (JPL)
in Pasadena, CA, and the other at a
Lockheed Martin facility in
Colorado, where the spacecraft
was built, were unknowingly
exchanging some vital information
The missing Mars Climate Orbiter
in different units.
Lost in space
DID YOU KNOW
The spacecraft team in Colorado
used English units of pounds of force
to describe small forces needed to
adjust the spacecraft’s orbit. The
data was shipped via computer,
without units, to the JPL, where the
navigation team was expecting to
receive the data in metric units.
The mix-up in units led to the JPL
scientists giving the spacecraft’s
computer wrong information, which
threw the spacecraft off course. This
in turn led to the spacecraft entering
the Martian Atmosphere, where it
The missing Mars Climate Orbiter
burned up.
DID YOU ALSO KNOW
Lost in space
On Jan. 3, 1999, NASA launched the
$165 million Mars Polar Lander. All
radio contact was lost Dec. 3 as the
spacecraft approached the red planet.
A NASA team that investigated the loss of the
Mars Polar Lander concluded a rocket engine
shut off prematurely (due to programming
error) during landing, leaving the spacecraft to
plummet about 130 feet to certain destruction
on the Martian surface.
The Gimli Glider
a mix up in units
On July 23, 1983 Air Canada
Flight 143 (a brand new Boeing
767) ran out of fuel while en route
to Edmonton from Montreal at
26,000 feet.
Miraculously the caption was
able to land the plane on an
abandoned Royal Canadian Air
Force Base at Gimli, where the
runways were converted into
two lane dragstrips for auto
racing. No one was killed.
The Gimli Glider
a mix up in units
On July 23, 1983 Air Canada
Flight 143 (a brand new Boeing
767) ran out of fuel while en route
to Edmonton from Montreal at
26,000 feet.
Miraculously the caption was
able to land the plane on an
abandoned Royal Canadian Air
Force Base at Gimli, where the
runways were converted into
two lane dragstrips for auto
racing. No one was killed.
SI Units of Measurement
(Metric System) p. 16
• LENGTH – straight line
btwn 2 pts.
–meters (m)
• MASS – amt. of matter in
object
–kilograms (kg)
• VOLUME – amt. of space
occupied by object
–liters (L)
Common Metric prefixes & values
Prefix
kilo
Multiple
hecto
100
h
deca
10
da
Base units
(meter, liter,
gram)
1
m, L, g
deci
centi
0.1 (1/10)
d
0.01 (1/100)
c
1000
0.001 (1/1000)
milli
Why scientists use metrics 2:31
Symbol
k
m
Kids
(kilo, 1,000)
Have
(hecto, 100)
Dazzling
(deca, 10)
Uniforms (Unit of measurement)
During
(deci 1/10)
Cross Country (centi 1/100)
Meets
(milli, 1/1,000)
10 mm = _______ cm
100 kg = ________ g
5296 mL = _____________ L
Other SI Prefixes (p. 17)
Prefix
Multiple
Symbol
Giga
Billion (109)
G
Mega
Million (106)
M
Micro
Millionth (10-6)
µ
Nano
Billionth (10-9)
n
Derived Units p. 16
Quantity
Unit
Symbol
Area
Square meter
m2
Volume
Cubic meter
3
m
Density
Kilograms per
cubic meter
kg/m3
VOLUME
English vs. Metric Units
Which is larger?
A. 1 liter or 1 gallon
B. 1 liter or 1 quart
C. 1 milliliter or 1 fluid ounce
1 gallon = 3.79 liters
It would take approximately 3 ¾
1-liter bottles to equal a gallon.
1 fl oz = 29.573 mL
1- 12oz can of soda =
approx 355 mL.
1 quart = 0.946 liters
Metric Units
Volume is amt of space object
occupies
Base unit is liter (L).
Standard: 1 liter = cubic decimeter
Which is larger?
A. 1 liter or 1500 milliliters
B. 200 milliliters or 1.2 liters
Click the image to
watch a short video
about volume.
C. 12 cm3 or 1.2 milliliters
Liter Image: http://www.dmturner.org/Teacher/Pictures/liter.gif
Measuring Volume
Read the measurement based on the bottom of the
meniscus or curve. Read at eye-level with level of
liquid.
What is the volume of liquid in cylinder? __________
What causes the meniscus?
A meniscus occurs when molecules
of
liquid attract molecules of
container.
Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif
Bottom Image: http://morrisonlabs.com/meniscus.htm
What is the volume of water in each cylinder?
Pay attention to the scales for each cylinder.
Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf
Measuring Liquid Volume
Measuring Solid Volume
8.2 cm
6 cm
We can measure the volume of regular object
using the formula length x width x height.
_____ X _____ X _____ = _____
We can measure the volume of
irregular object using water displacement.
Amount of H2O with object = ______
About of H2O without object = ______
Difference = Volume = ______
Click here for an online activity about volume.
Choose Lessons  Volume & Displacement
http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/e
n/syllabus/unit14/new/testingmain1.htm
9.0 cm
MASS
Which is larger?
English vs. Metric Units
1. 1 Pound or 100 Grams
2. 1 Kilogram or 1 Pound
3. 1 Ounce or 1000 Milligrams
1 pound = 453.6 grams
1 oz gold = 28,349.5 mg
100 kg = 220 pounds
Metric Units
Mass - amt of matter in object.
Base unit is kilogram (kg)
Standard: 1 kg = mass of International Prototype Kilogram
(IPK), a platinum-iridium cylinder kept by the Bureau
International des Poids et
Mesures (International Bureau of
Weights and Measures [BIPM]) .
Which is larger?
A. 1 kilogram or 1500 grams
C. 12 milligrams or 12 kilograms
B. 1200 milligrams or 1 gram
D. 4 kilograms or 4500 grams
Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram
Kilogram Prototype
Click the image to
watch a short video
about mass.
Measuring Mass
Objects placed on pan
Starting with largest weight,
move weights on beams until
lines match up.
Once you have balanced the scale, you add
up the amounts on each beam to find the
total mass.
What would be the mass of the object
measured in the picture? (precision to
nearest 0.01g)
_______ + ______ + _______ = ________ g
Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpg
Bottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg
Measuring Mass – Triple-Beam Balance
1st – Place the object to be massed on the pan.
2nd – Slide the large weight to the right until the arm drops below the
line. Move the rider back one groove. Make sure it “locks” into place.
3rd – Repeat this process with the top weight. When
the arm moves below the line, back it up one groove.
4th – Slide the small
weight on the front
beam until the lines
match up.
5th – Add the amounts on each beam to find the total mass to the nearest tenth (0.1)
of a gram. Estimate your final digit to the nearest hundredth (0.01) of a gram
Click here to try an online activity.
Which has more mass – water or
steel?
• Large amt of water could have more mass
than small amt of steel
• To compare, must compare masses that
occupy same volume or compare
volumes of same mass
How do you define DENSITY?
• Density - ratio of material’s mass to
volume
• For example: A steel shot put is more
dense than a styrofoam ball of the same
size.
• Or…how closely "packed" material is rock vs. crumpled paper or “cereal killer”
• Each sample has same volume. If each red
particle has the same mass, which box
would weigh more? Why?
• Sample w/ more particles has more mass
per unit of volume. The density of a
material helps distinguish it from other
materials.
Science of NHL hockey – Mass, volume and density 6:27
Limits of Measurement
Precision gauges how exact a
measurement is
• How precise are the
clocks on the right?
• Top analog clock is
precise to the minute
• Digital clock is
precise to the
NFL flyovers 4:53
second
Accuracy is closeness
of a measurement to
actual value
This clock is running 15 minutes
slow……
 precise to nearest second BUT
 time not accurate
What are scientific measurements? 9:45
Significant figures
(digits)
• “Sig Figs” - all digits of known
measurement + 1 estimated digit
• Answer can only be as precise as
least precise measurement in
calculation
• more precise, more sig figs
Sig Fig Rules
• ALL non-zero #’s are
always significant.
• Zeros btwn two sig
figs are significant.
• Trailing zeros only
significant after
decimal
Not sig figs
How many sig figs?
3 sig figs
1) 50.5
4 sig figs
2) 26.25
1 sig fig
3) 500
3 sig figs
4) .050
5) 1.0250 5 sig figs
Example
• You’re curious about the
average time it takes you
and your friend to walk to
Quik Trip to get a slushy.
You take 3 minutes 15
seconds (3.25 min) from
your house. Your friend
takes 4 minutes 30 seconds
(4.5 minutes) from her
house.
3.25min + 4.5min = 7.75 total min
7.75min / 2 = 3.875 min
This answer has 4 sig figs, but least
precise number in calculation has only
2 sig figs (4.5 min)
Therefore, answer can only have
TWO sig figs
Your answer is 3.9 minutes (rounded
up)
Measuring Temperature
• 3 temp scales:
– Fahrenheit
• H2O freezes @ 32°F
• boils @ 212°F
– Celsius
• H2O freezes @ 0°C
• Boils @ 100°C
– Kelvin (SI base unit for temp)
• 0 K – lowest possible temp (= -273.15°C)
• K = °C + 273
Sec. 1.4 Presenting Scientific Data
p. 22
• Scientists organize data in data tables &
graphs
Data Tables
• Relates independent & dependent
variables
• Organizes
data
Independent variable
dependent variable
Ordered Pair – set of data directly related
• Show changes in
related variables
Line Graphs
– Often change over
time
• Independent
variable plotted on
x-axis.
• Dependent
variable plotted on
y-axis.
• Shows continuous data
• interpolate/extrapolate unknown data
What does this
measure?
DENSITY!
Rise 2 min
=
Run 0.5 gal/min
Rise 0.5 min
=
Run 2 gal/min
Bar Graphs
• compares set of
measurements,
amounts, or
categories
• non-continuous
data
• generalizes data
• data differences
Circle Graphs
• part to whole
• Entire
circle=100%
• slices are %
that add up
to 100%
With 32,500
households
surveyed,
how many
households
relied on
steam for
heat?