Upload
bruce-jennings
View
226
Download
0
Tags:
Embed Size (px)
Citation preview
21
ScScandium
45
53
IIodine
127
10
NeNeon20
58
CeCerium
140
…is a method of obtaining knowledge about the world through observation and experimentation. Science uses testable explanations and makes predictions about the universe.
Time to Spend Studying by Course
Hierarchy of Science
Logic and Mathematics
Physics and Chemistry
Biological
Ecology
Cellular
Biochemistry
Molecular
Earth Science
Astronomy
Meteorology
Geology
Oceanography
A knowledge of physics and chemistry makes other sciences easier!
“But that’s just a theory…” “Science has
Proven…”
Batman, evolution is just a theory…
A scientific theory is very well evidenced
you idiot!
Aristotle (384-322B.C.) claimed that an object that was twice as heavy as another object would fall twice as fast. This HYPOTHESIS is testable but apparently it never dawned on Aristotle to conduct an experiment.
2lbs1lb
Galileo (1564-1642) conducted experiments where he rolled balls of different masses down inclined planes. The results conclusive showed that objects fall at equal rates regardless of their weight.
Galileo also dropped objects of different masses off the Leaning Tower of Pisa. The result: they hit at the same time regardless of their mass difference.
Aristotle had monumental authority as a great thinker in antiquity and his hypothesis was accepted by many for nearly 2000 years until Galileo tested it. In science, experimentation and data trumps everything.
Metric System and Units
Metric System is based upon powers of 10.
SI vs English UnitsUnit Name and
Symbol Murica What does it measure?
Meter| Kilometer Feet | Miles Length
Gram | Kilogram Ounce | Pound Mass
Second Seconds Time
Kelvin or Celsius Fahrenheit Temperature
Converting Units is ImportantCountries in Red have not adopted the SI system of measurement.
Collaboration
1. Nasa MCO2. Gimli Glider
3. Overpriced Rice4. Medication
Stoichiometry!
Base, Derived and Special Units!
• What is the difference?
7 BASE SI Units
Unit Name and Symbol Dimension Symbol What does it
measure?
Meter (m) L
Kilogram (kg) M
Second (s) T
Ampere (A) I
Kelvin (K) Θ
Mole (mol) N
Candela (cd) J
7 BASE SI Units
Unit Name and Symbol Dimension Symbol What does it
measure?
Meter (m) L Length
Kilogram (kg) M Mass
Second (s) T Time
Ampere (A) I Electric Current
Kelvin (K) Θ Temperature
Mole (mol) N Amount of substance
Candela (cd) J Luminous Intensity
Other units are DERIVED units
• Meters/Second• Miles/Hour• Feet/Second
• Energy = joules• 1 Joule = kg m2/s2
• Feet/Second
• g/cm3
• m/kg3
Some Units Get Special NamesScientists are Lazy!
• A NEWTON is the force required to accelerate a one kilogram object at a rate of one meter per second squared.
Instead of writing (kg)(m)/(s2) physicists just use Newton (N) instead.
• Thus 1N = 1(kg)(m)/(s2)
Pressure = Force/Area
• Force = (kg)(m)/(s2) • Area = m2
• Units for pressure
= 1 Pascal=
Units on One side of an Equation must equal the units on the other
• Meters/Second• Miles/Hour• Feet/Second
• Energy = joules• 1 Joule = kg m/s2
• Feet/Second
• g/cm3
• m/kg3
Units on One side of an Equation must equal the units on the other in order to
be dimensionally correct!
• This formula is saying a measure of length divided by some measure of time is equal to half of a mass squared. Is this valid?
• Speed in miles/hour = a distance (miles) divided by a time (hours). This is valid.
Metric Mania
• How many feet long is the room?
• Who tells a ruler how long to be?
• The Royal Foot vs Standard Foot
• We need a standardized system.
What Ruler Measures Rulers?
1ft = 12in
1ft = 12in
m-k-s systemA Meter is defined by the speed of light. A meter is defined as the length light will travel in 1/299792458 of a second.
A kilogram measures mass and it is equal to an international prototype. Meaning there is an object in a museum that was arbitrarily chosen to have a mass of 1kg. All other masses (including pounds, grams, etc.) and weight are based upon this object.
A second is defined as the duration of 9,192631770 periods of the radiation of a cesium atom between two hyperfine levels of the ground state cesium-133 atom.
Img via BIPM
Conversion is Easier
Three Yards into Feet
• 3 goes to 36• We have a new number.
Three Meters into Centimeters
• 3 goes to 300• Decimal moves two places
Just moves the decimal to left or right. Much more convenient especially when dealing with the very large and small numbers of science.
Conversion is Easier
5 miles into feet 5 kilometers into meters
Metric System is a Base 10 system (think Scientific Notation!) where decimals move.
LADDER METHOD
Decimal moves to the right.
Decimal moves to the left.
Kilo1000 units
BASE1 unit
Hecto100 units
Deka10 units
Deci0.1 units
Centi0.01 units Milli
0.001 units
Decimal moves to the right.
Decimal moves to the left.
100
101
102
103
10-3
10-2
10-1
Conversions:
155cm m25km m2km cm
3,400mL L3.4L mL
256g kg45kg g
KING HENRY DIED BY DRINKING CHOCOLATE MILK
Base Units:
MeterLiterGramSecond
tera
giga
mega
pico
nano
micro
milli
deci
centi
Base
Deka
Hecto
Kilo
101
103
102
106
109
1012
100
10-1
10-2
10-3
10-6
10-9
10-12
1 Unit
1,000,000 Units
1,000,000,000 Units
1,000,000,000,000 Units
0.01 Units
100 Units
10 Units
0.1 Units
0.001 Units
0.000001 Units
0.000000001 Units
0.000000000001 Units
1,000 Units
Decimal moves to the right.
Decimal moves to the left.
Tera = TGiga = G
Mega = MKilo = k
Hecto = hDeka = da
Deci = dCenti = cMilli = mMicro = μNano = nPico = p
Meter Liter Gram Second
Base Units:
Assignment• What is the difference between base, derived and special units? Provide two examples of
each? Do not use the special units covered in this presentation.• Why is a standard international set of units helpful and necessary in science?• Should the United States Adopt the Si system of measurement? What changes would this
entail? How much would it cost?
• Convert the Following Units using the stair step method:• 360cm _____m 2345mm _____m 25m _____km 2,345cm _____da • 400mL _____L 2L _____mL 234dL _____mL 13kL _____ L
• 934g _____kg 2.3kg _____g 445mg _____g 0.4kg _____g
• Compare using <, > or = to.• 56cm 6m 7g 698mg 1500mL 1.5L 1500mL 1.5L
• 43mg 6g 36cm 0.36m 3,445mL 3.5L 5kg 500g • The ceiling in Mr. O’Connell’s living room is 2.4 m high. He has installed a new hanging lamp
that hangs down 61 cm. He is approximately .175dekameters tall. Will he hit his head on the hanging lamp? Draw a sketch and show your work!
Rules for Converting Units1. Units cancel in division.2. Units combine in multiplication.3. Units stay the same in addition and subtraction.
What is a Conversion Factor?1. A ratio written in fraction form that can express the
same value or quantity in two different units. 2. Conversion Factors are going to essentially equal one.3. Any number multiplied by one does not change.
How many inches are there in 50 feet?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
How many inches are there in 50 feet?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
xft =50ft
in in121
600
How many feet is 744 inches?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
How many feet is 744 inches?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
in744
How many feet is 744 inches?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
xin744
How many feet is 744 inches?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
xin =744in
ft ft
How many feet is 744 inches?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
xin =744in
ft ft
121
How many feet is 744 inches?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
xin =744in
ft ft
121 62
Basic Template
x =
Unit you want to change
Unit you are changing into
Conversion
Factor
How many seconds are 3 hours?
1. Start with the unit you want to change.2. Multiply it by a blank fraction.3. The unit you want to change goes in the denominator.4. The unit you want to convert into goes into the
numerator and answer.5. Insert the values for your conversion factor.6. Solve the problem.
How many seconds are there in a day?
How many seconds are there in a day?
Convert 60mi/hr into m/s!1 mile = 1.609km.
Convert 60mi/hr into m/s!1 mile = 1.609km.
CONVERSION PROBLEM OF THE DAY: If someone were to drink 18 cans of Guinness at 14.9 Fl.Oz. per can and there are 130 calories per 12oz, how many calories did that person drink?
CONVERSION PROBLEM OF THE DAY: If someone were to drink 18 cans of Guinness at 14.9 Fl.Oz. per can and there are 130 calories per 12oz, how many calories did that person drink?
Which one is the better deal? How much do you pay for one pad in each case?
If Mr. Sapone eats a whole bag of Doritos, how many calories will he
consume?
How much does one Dorito cost?
How many calories are there in one Dorito?
If one fruit by the foot roll is 3 feet long, how much does 4 feet of Fruit by the Foot cost?
Unit Conversions1. On the planet Shnoidia, everyone earns 80 Quatloos a day. One Zerumba (a favorite food item)
costs 7 Quatloos. How many Zerumba’s can be purchased if someone works for 3 days?2. A clock goes from 1:15pm to 12:30am, how many seconds went by?3. A shark swims 35 ft/s. Express this speed in mi/hr assuming 1 mile is 5,280 feet.4. There are 3 teaspoons in a tablespoon, 16 tablespoons in a cup and 16 cups in a gallon. How many
teaspoons are in a gallon?5. Eggs are shipped from the farm to market by truck. They are packed 12 eggs to a carton and 20
cartons to a box. Four boxes are placed in each crate. Crates are stacked on a truck 3 crates wide, 3 crates deep and 2 crates high. How many eggs are on the truck?
6. If your heart beats 72 times per minute, how many times does your heart beat in a day.7. How many hours are there in 5 and a half weeks? 8. The new hybrid cars get 65 miles per gallon. How many miles can you drive on 5 gallons of gas? 9. How many nickels are in 126 dollars? 10. On your 18th birthday, how many minutes will you have lived?11. A single rain drop is made up of about one million cloud droplets. How many cloud droplets make
up 150 rain drops? 12. How much does 1 Hershey’s kiss cost assuming a bag costs $4.99 and the label tells you the
following information:Serving Size 9 pieces Servings per container 13 Calories per serving 200
13. How many calories are in the whole bag?
Scientific Notation
What is it, why do we need it and how do we do it.
Scientific Notation
• How long would it take to count to one million?
• How many atoms are in one cup of water?
• What is the mass of the earth in grams?
• What is the rest mass of a single electron?
Scientific Notation
23 days.• It might not seem like it
but a million is a big number but small when compared to other much larger numbers in science.
Scientific Notation
24,000,000,000,000,000,000,000,000
• One glass of water has that many atoms in it. That is more atoms than there are cups of water in all the oceans.
Scientific Notation
24,000,000,000,000,000,000,000,000
• One glass of water has that many atoms in it. That is more atoms than there are cups of water in all the oceans.
sextillion septillion quintillion quadrillion trillion billion million thousand hundred
Scientific Notation
6,000,000,000,000,000,000,000,000,000g
The mass of the earth!
Scientific Notation
The rest mass of a single electron!
0.000000000000000000000000000000911kg
Scientific Notation
Which number is easier to use?
0.000000000000000000000000000000911kg or 9.11x10-31kg
24,000,000,000,000,000,000,000,000g or 2.4 x1025
6,000,000,000,000,000,000,000,000,000g or 6 x1027
Calculating the force of gravity the sun exerts on the earth.
Multiplication and Division are easier!
Scientific Notation
An abbreviation for very large and very small numbers in science.
1a) Identify five objects smaller than the eye can see.1b) Briefly Describe what the object is.1c) Express its size in scientific and standard notation.
2a) Find five objects bigger than the sun.2b) Briefly Describe what the object is.2c) Express its size in scientific and standard notation.
3) Is the sun a large object on astronomical scales?
4) What is scientific notation and why do we use it?
Click the Picture of a Link, if that is Down Click Here.
Order of Magnitude: Using the scale of the universe app, what order of magnitude do the following objects have in meters?
Express them in scientific notation and include a fact about them.
• A Human Being• Titanic• Boeing 747• Hummingbird• Mitochondrion• A Blue Whale• Angel Falls • Tyrannosaurus Rex• String• Up Quark• Water Molecule• Mount Everest• Ant• Ganymede• Proxima Centauri
• Observable Universe• Total Human Height• Sirius A• Kuiper Belt• Gomez’s Hamburger• Glucose• Tarantula Nebula• Andromeda Galaxy• A Light Year
ESTIMATE• Height of School• Telephone Pole• Length of CT• Distance of US
• Length of Mall• Height of Holy Land• Diameter of Golf Ball• Length of Pencil• Thickness of Paper
The Number of Golf balls that could fit:
• On a school bus.• In a suitcase• In our classroom• In a bathtub
BINGO! Guess How Many Jelly Beans are in the Jar and Win it!
Some number written in the form A x 10B
one non-zero number to the left of a decimal point.Move decimals left or right and count the spaces.
Moving Left = positive exponent (big numbers)Moving right = negative exponent (small numbers)
Multiplying or Dividing a
number by 10 ONLY moves the decimal point!
100 1000 24,000
365,445 2
0.0010.000001
0.00009045.03 x 106
4.3x10-8
1. Where is the decimal?2. Where do I want it?3. How far did I move it?4. Negative or Positive?
1234 1,020,000
18,30054,234,0124 million
0.00109
0.00000000340.0000904
1/1012 thousandth
2.345x109
3.03 x 108
2.1x10-6
9x10-31
Convert to Scientific Notation
Convert to Standard Notation
• Rule 1
• Example
• Rule 1
• Example
Multiply the leading numbers and add the exponents!
Calculating the force of gravity the sun exerts on the earth.
6.67 x 1.9891 x 5.97219 x 10 (-11 + 30 + 24)
1.496 x 1.496 x 10 (11+11)
(3x108) x (6x101) =
(2.235x108) x (6.453x101) =
• Rule 2
• Example
• Rule 2
• Example
Divide the leading numbers and subtract the exponents!
(8x108)(4x101) =
(3x104)(6x107) =
Exponent Rules
• Proof from Rule 1:
• Example
(2x102) + (4x101) =
(2.5x104) + (4.4x103) =
Convert to same power.Keep the exponent.Add the leading numbers
(4.45x109) x (3.43x100) =(2.5x105) x (3x106) =(4x1013) x (3x102) =(2x104) x (3.5x102) =(2.5x104) - (4.4x103) =(2x102) - (4x101) =(3.6x105) + (4x106) =
Convert to same power.Keep the exponent.
Add the leading numbers
Multiplying
Multiply the Leading numbersAdd the Exponents
Divide the Leading numbersSubtract the Exponents
Dividing
Adding and Subtracting(9x106)(3x104)
(9.34x106)(3.85x104)
(4x104)(8x106)
(12x106)(3x107)
=
=
=
=