Transcript Document

Biology Objective 3
Demonstrate an understanding of the
interdependence of organisms and the
environment.
Biomes
Identified by biotic and abiotic factors
• Biotic – what kinds of plants and animals live in it.
• Abiotic – Nonliving characteristics such as soil
type, rainfall amounts, and average temperature
cycles.
Temperate Desert
Forest
Name
Tundra
Grasslands
the
Biome
Tropical
Tiaga
Rainforest
What are they referring to?
• Biosphere – The entire
area of the planet that
supports life.
• Biome – An area defined
by specific abiotic and
biotic factors.
• Community – The groups
of living things in an area
and how they relate.
Ecology – The study of the
relationships among living things
• Symbiosis is a close relationship between
two living things.
• When both are helped it is called mutualism
• When one is helped and there is no effect on
the other it is called commensulism
• When one is helped and the other is harmed
it is called parasitism
Mutualism . . .
Sharks are cleaned by
a little fish known
as a Remora. The
shark never eats
them since they
clean bacteria off of
the shark. Since
both species are
helped, this is
mutualism.
Commensulism . . .
Orchids live high
in tree-tops on
the branches of
large trees. They
do not harm the
tree, but they are
helped by being
raised up into the
sunshine and
receiving water.
Parasites . . .
Parasites harm or
kill the host. A
good example is
a tape worm. It
intercepts all of
the hosts food,
causing the host
to starve to death.
35 Clown fish are small reef fish that seek protection
from predators by sheltering themselves among the
stinging tentacles of sea anemones. Clown fish are
very territorial and can potentially scare off
predators of sea anemones. This relationship is an
example of -A neutralism This is not a type of symbiosis Incorrect
Since both are helped, it
B mutualism
is of mutual benefit or
C parasitism Neither is harmed so this is incorrect
D commensalism
Means only one is being helped and the relationship
has no effect on the other – also incorrect
What is helped?
Both the ants and the tree.
This is the definition of:
All energy on the earth comes
from the sun.
Energy Diagrams
At one end of the diagram are plants.
They are called producers since they
are capable of turning sunlight into
food by photosynthesis. They pass
10% of the energy they absorb to
animals that eat them.
Consumers
1st Order Consumers eat
only plants and are also
called herbivores.
2nd Order Consumers eat
only animals and are
called carnivores.
3rd Order Consumers
animals that eat other
animals, they are also
known as carnivores
39 Wolves and hawks are at the same Trophic
trophic level
level
because they —
Means 1st ,
A both live on land
2nd or 3rd
B are both large mammals
Order
C both eat primary consumers
Consumer
D have similar hunting patterns
10% Energy Rule –
Only 10% of the energy moves up to
the next trophic level.
Decomposers
If we apply the 10% rule, 10% of
43 Approximately how much
the 1000 kcal of the plant is
of the energy available in the
consumed or 100 kcal, and 10%
tissues of the producer is
of that is 10 kcal which is 1% of
eventually incorporated into
the original 1000kcal, but only 3
the tissues of a secondary
kcal is available to the tissues so
consumer?
it is A.
A Less than 1%
B Between 20% and 30%
C Approximately 50%
D More than 50%
Food Chain – One of many
feeding relationships in a
community
• Arrows in a food chain
show the direction of
energy flow.
• This is not the only
feeding relationship
for these organisms.
• When several or all of
the food relationships
are shown it’s a . . .
Food Web
Food Webs
• Food webs attempt to show all the feeding
relationships in a community.
• The direction of the arrows shows the
direction of energy flow.
• At the bottom of every web and every chain
is a plant. These are the only things that can
turn sunshine into food.
Since the Gulls are at the
top of the food web, they
would have the highest
accumulation of everything
but energy.
37 Which of these groups of
organisms would most likely
have accumulated the largest
concentration of a long-lasting
chemical pollutant in their
bodies?
A Phytoplankton
B Zooplankton
C Lake trout
D Gulls
• Prey are the animals
that are eaten as a food
source for the . . .
• Predator This is the
hunter animal. The
population of the
predator must be less
than the prey or they
do not have enough
food.
Population (100s)
Predator and Prey
Time (months)
Prey
Predator
To increase the predator
population you could do what?
24 Which of the following is most likely
to cause increases in a predator
population?
F Fewer prey Reduces available food – Nope!
G A reduction in competition
Less predators, they
H More parasites would
Less
and prey,
bepredators
sick or dying!
J A period of drought they’d be gone looking for
water!
Population (100s)
Carrying Capacity
Time (months)
P rey
P redat or
• This is the maximum number of a specific
population that an area can support with enough
food and living requirements. It is shown by a
line on population graphs for a specific species.
Water Cycle
• Precipitation (rain
and snow) fall on
plants and ground.
• Plants respire and
evaporate water
back into clouds.
• The ground filters
the water run-off
into the lakes
where it
evaporates again.
21 The diagram
shows physical
changes that
occur in the water
cycle. Which of
these shows
condensation?
A Q Precipitation
B R Run Off of
ground water
C S Evaporation
DT
Carbon Cycle
• Glucose C6H12O6 is
produced by plants,
eaten by animals.
Photosynthesis
• Animals and plants
exhale CO2 which is
taken in by plants to
make glucose
Cellular Respiration
Nitrogen Cycle
Nitrogen Cycle
• Lightening and bacteria in the ground “fix”
Nitrogen into a form usable by plants.
• It is absorbed by plants, through their roots
as nitrates, so they can be used to build
amino acids essential for building proteins,
enzymes and the nitrogen bases of DNA.
Rock Cycle
Man’s Effects on the Environment
• Ozone O3 is a protective layer at the top of the
atmosphere.
• However, when it occurs near the ground, it is
very harmful to all living things, it is SMOG
Man’s Effects on the Environment
• More than 90% of
fresh water is locked
in ice at the polar
caps and in glaciers.
• Much of the fresh
water is polluted by
land run-off, dumping
of wastes and excess
heat directly into
lakes, oceans and
rivers.
Man’s Effects on the Environment
Global warming, also
called the Greenhouse
Effect is caused by
excess burning of fossil
fuels and destruction of
our oxygen producing
protista in the oceans,
and deforestation on
land. Less plants
means less oxygen and
more CO2.
Evolution:
The process of change over time.
• There are natural variations in all populations.
• As climate changes occur, and as pressures in
terms of food, space, shelter and predation
occur, some variations allow a species to
survive.
• The members who survive, reproduce causing
the change to become a characteristic of the
species.
Speciation:
Separation into new species.
• Geographic isolation
can cause two
different natural
variations to become
prominent causing 2
separate species.
• Reproductive isolation
can have the same
effect.
What is extinction and what causes it?
• A population is extinct when the last of that species is
dead.
• Example: There are no more dinosaurs.
• What happened? Their habitat was destroyed. When
they no longer have what they need to live, they die.
Fossils
• These are imprints or
remains of living things.
• In undisturbed layers of
sedimentary rock, the
deeper it is, the older it
is.
• Give us information
about extinct species.
Homologous vs. Analogous Structures
• Homologous means they • Analogous means they
have the same origin, but
have the same function but
may be different now.
come from different
origins.
• Example, the upper arm
bones in dogs, cows, cats • Example, bird wings and
and monkeys.
wings of bats.
Viruses
• Viruses are not alive
because they can not
reproduce on their
own, and
• They do not grow and
develop and
• They do not exchange
with their environment
Viral Illnesses
• Measles, mumps, colds,
influenza, Cold Sores,
mononucleosis, Epstein-Barr
virus are all illnesses that are
caused by a virus.
• A Virus is has a coat, a strand
inside of DNA or RNA, and some
type of attachment appendage.
Bacteria
• Bacteria can cause illnesses too, however 90%
of all bacteria is helpful, NOT harmful.
• Without bacteria, you would not be able to
make or eat cheese or ice cream. Without them,
you would be ill most of the time.
• Strep Throat and Staph infections are examples
of bacterial infections.
Class TAKS Review
Objective 4
Matter and Change
Matter
• Anything that
has mass and
takes up
space.
• Energy is
NOT matter
Matter is divided into 3
types:
• Elements
• Compounds
• Mixtures
The 3 types can be further
separated in two categories:
• Pure Substances
• Elements are the
simplest pure substances
• Mixtues are not
pure substances
Compounds
which
and wewhen
will two
deal
are formed
or more
withelements
them inshare
a few
electrons or become
minutes.
ions that attract other
elements.
Atoms are. . .
• The smallest part of a
single element.
• The basis of all matter.
• Made of mostly empty
space.
• Have a positive core or
nucleus.
• Have electrons in orbit in
clouds.
4 Basic Types of Elements
• Metals: found on the left and center of the Table
of Elements
• Non-metals: found on the right side of the Table
of Elements
• Metalloids: found along the stair-step line
• Synthetic: made in the laboratory and not yet
found in nature – many of the Actinide and
Lanthanide series and very large # elements.
Where are the metal elements?
Left of the Stair-step line!
Properties of Elements Metals
• Metals are:
– Conductors
– Lustrous
– Electron donors
– Malleable
– Ductile
Where are the nonmetals?
To the Right of the stair step line, and Hydrogen!
Properties of Nonmetals
• Nonmetals are brittle, insulators, electron
acceptors
• Usually form negative ions (except H)
• Many are gases at room temperature
• Found to the right of the stair-step line
23 According to the periodic table,
which element most readily accepts
electrons?
• A Fluorine
•Fluorine
B Nitrogen
only needs 1 electron
• This is a nonmetal, so it accepts
to electrons
completebut
its itshell
of 8,share
so it
will also
1-.
them
as initNO
will
accept
from
any other
3
•element
C Arsenic
very very very easily.
• This is a metalloid, so it only
This
periodicaccepts
property
sometimes
electrons.
increases
as you move up and
• D Aluminum
left
in the
except
for the
• This
is a table,
metal so
it donates
electrons.
Noble
Gases.
The BOHR Model of an Atom
• This is the first model to
have a nucleus with
protons and neutrons.
• The electrons are in
various energy levels and
circle the nucleus.
• Model most people draw
today.
Use the Table provided!
What do the numbers mean?
11
Na
22.990
sodium
This is the atomic number.
It is the number of protons
in a single atom of this
element. By the way, its
also # of electrons.
The symbol for this element.
This is the atomic mass, it is the
number of protons + neutrons,
or the mass of the nucleus of an
atom.
This is the name of the element.
Diatomic Elements –
Nonmetals that come as molecules
• 7 Elements are di- (2) atomic (atoms)
• The easy way to remember them is by
the name
•Br I N Cl H O F
3 Which of the following groups
contains members with similar
chemical reactivity?
A Li, Be, C
B Be, Mg, Sr
C Sc, Y, Zr
D C, N, O
Lets look at the Table provided.
• To have similar
chemical properties
of any kind, they
must be in the same
Group or Family.
• Groups are
columns, so the
answer would be
•B
Chemical Reactivity
• Metals increase in
reactivity left and
down.
• Nonmetals
become more
reactive up and to
the right.
• Most reactiveF
metal is?
r
• Most reactive
nonmetal is?F
Changes in Matter –
Physical or Chemical?
• Physical changes are changes in the state of matter.
They do not change the substance. (Melting, boiling,
condensing, freezing, cutting)
• Chemical changes are reactions that result in new
products with new properties.
Changes in Matter –
Physical, Chemical or Nuclear?
• Physical changes do not • Chemical changes are
change the substance.
also called chemical
The state of the matter
reactions.
may change, but it keeps • When a different
its own properties.
substance is produced
• Cutting a piece of wood
than what was present
does not change the
at the start, a chemical
wood, it is simply
change has occurred.
smaller.
Nuclear Changes: Fission and
Fusion
• Fusion occurs when
the nucleus of one
atom is joined by the
nucleus of another.
• This is the reaction
that occurs on the sun
and stars.
• It produces extreme
energy release.
• Fission occurs when the
nucleus of an atom ejects
particles and energy when
hit by a subatomic particle
such as a neutron.
• This also causes a release
of extreme energy and is
the basis of atomic energy
plants and bombs.
Density = Mass / Volume
THIS IS FROM THE FORMULA
PAGE
25 A block of maple wood with a volume of
405block
cubic
centimeters
density
If the
is cut
in half, youand
cut athe
mass inofhalf AND
3 is sawed in half. The density
g/cm
you0.67
cut the
volume
in half, so Mass/2
or
Volume/2
of the two smaller blocks
is now —
A one-fourth
original
density
Mass x 2the(which
is really
1) so . . . .
Volume the2 original density
B one-half
C two times the original density
D the same as the original density
20 A sample of an element has a volume of
78.0 mL and a density of 1.85 g/mL. What is
the mass in grams of the sample? Record and
bubble in your answer to the nearest tenth on
the answer document.
Use the formula page, D = M/V
x
1.85 g/mL =
78.0 mL
Multiply both sides by 78.0 mL and you get:
144.3 g Grid it in!
Law of Conservation of Matter
• Matter can not be created or destroyed.
• The total mass of the substances before they are
mixed is equal to the total mass as a mixture.
Chemical
Reactions
Since matter can not be
Reactants  Products
created or destroyed,
chemical reactions
100g total = 100g total
must be balanced in
terms of mass.
The amount of mass you
start with must be equal
to the mass of the
products.
39 According to the law of conservation of
mass, how much zinc was present in the zinc
carbonate?
Since matter can not be created or destroyed in chemical
A 40 g
B 88 g
C 104 g
D 256 g
reactions, the mass on both sides of the arrow must be equal.
So
64g + 192g = 256g and 152 g + Zinc = 256g
There must be 104g of Zinc. Answer C.
Chemical Equations
• Whole numbers written in front of formulas are
called coefficients. For example, 4 C6H12O6
indicates that there are 4 molecules of glucose
sugar.
• To determine how many total atoms of each element
are present, multiply the coefficients by the
subscripts for each element.
• 4 C6H12O6 would contain 24 atoms of carbon
(4 x 6), 48 atoms of hydrogen (4 x 12), and 24 atoms
of oxygen (4 x 6).
To balance equations:
• The number of atoms of each type of element on the
reactant side (left of the arrow) must be equal those
on the product side (right side of the arrow).
2 H2 + O2
2 H2O
• There are 4 hydrogen atoms on the left (2 H2) and 4
hydrogen atoms on the right (2 H2O)
• There are 2 atoms of oxygen (O2) on the left and 2
atoms of oxygen on the right (2 H2O). When a
subscript is missing, it is understood to be 1.

2
K +2 H H
OH
2O  2 KOH + H2
19 What is the coefficient for H2O when
the above equation is balanced?
• A 1 To balance this equation, make water
HOH, then you will see that you need 2 H
• B2
and get 2 OH groups.
• C3
That means the KOH gets a coefficient of
• D 4 2, the K gets a coefficient of 2 and
The water must also get a coefficient of 2.
Balance the equation below, the
boxes should get the coefficients.
2
2
Which element does not have the same number of
atoms on both sides? Oxygen. It has 2 on the reactant
side and 3 on the product side. If we put a coefficient
of 2 in front of PbO, we will now have 4 O and 2 Pb on
the right. By placing a coefficient of 2 in front of the
reactant, we have 2 Pb and 2 x 2 O. That means it is
balanced! Answer?
C
The 3 types can be further
separated in two categories:
• Mixtures
are
• Pure
Substances
notCompounds
pure substances.
which
are formed
when its
two
Each part of a mixture
keeps
more
elements
own properties,orand
can
be share
electrons or become
separated out byions
a physical
that attractchange.
other
• Elements are the
simplest pure
substances
elements.
Decide if the substance is
Element, Compound , or Mixture?
1. Water
1. Compound
2. Table Salt
2. Compound
3. Oxygen
3. Element
4. Dirt
4. Mixture
5. Air
5. Mixture/Solution
Click Mouse button to see answers!
Let’s try a few more!
6. Copper
6. Element
7. Soda
7. Solution/Mixture
8. Steel
8. Solution/Mixture
9. Rain
9. Mixture
10. Ice-cream
10. Mixture
Click Mouse button to see answers!
Properties of Mixtures:
•Each substance retains
its own properties.
•Substances can be
sent in any amount.
•Substances can be
arated by simple
a l m e a n s.
pre
sep
physic
There are two types of
mixtures:
• Heterogeneous• Homogeneous- same
mixture is not the
composition throughout.
same from place to
place.
– Kool-aid, air, brass.
– Chocolate chip
cookie, gravel, soil.
Separating Mixtures – Physical
Changes
• Separation of mixtures
could be:
• Magnetic removal (if
there is Fe, Ni, Co)
• Filtration (if there are
large particles)
• Hand sorting particles
• Decanting (pouring off
the less dense liquid)
Another technique for
separating
mixtures:
Evaporation:
changing from a
liquid to vapor
state– leaves
behind the other
component.
Distillation:
– Process used to
remove vapor from
liquid by heating
– Great for
separating two or
more liquids which
have different
boiling points.
So, what is a suspension or colloid?
•o Suspensions
Colloids havehave
small
larger
particles,
particlesoften
that are
visible
not in
size.
visible by just looking. An
example would be coffee.
o The particles can be
•filtered
However,
out. they show the
Tyndall Effect (see the
o It
scatters
laser
light light
line).– No
Tyndall
Effect.
• They can not be separated
filtering.
o by
If left
undisturbed, the
particles will settle to the
bottom.
Solutions: 2 parts
–S o l v e n t - t h e m o s t
abundant substance
in the solution.
–S o l u t e - t h e l e a s t
abundant substance
in the solution.
– Homogeneous: You can not see any
particles of either part!
The three methods to increase
the rate of solution for a solid
are?
•Heat it!
•Crush it!
•Stir it!
the amount of each solute
that will dissolve in 100g
H20 at each temperature.
Saturated is on the line.
Unsaturated is below the
line.
Supersaturated is above
the line.
Grams solute/100 g
H2O
How much solute will
dissolve?
A solubility curve shows
Try this one!
49 According to the graph,
about how much
hemoglobin would be
saturated at an O2
pressure of 7.3 kPa?
A 32%
B 67%
C 89%
D 92%
Concentrated or Dilute?
• A concentrated
solution has as little
solvent as possible.
• A dilute solution has
added solvent.
• After adding more
solvent, there is still
the same mass of
solute that you started
with.
pH is a measure of the
Strength of Acids & Bases
• Acids have 0-6.99 pH
• Bases have 7.01-14 pH
• Remember because A
begins the alphabet and
zero begins numbers
• Litmus turns red in acids
and blue in bases
• Phenothalein turns pink in
a base and stays clear in
acids.
Higher pH levels means?
33 Two clear solutions are placed in separate
beakers. The first solution has a pH of 4, and the pH
of the second solution is unknown. If
the two solutions are mixed and the resulting
pH is 5, the second solution must have —
A fewer
suspended
solids and have no
Solutions
are homogeneous
Nothing
is mentioned
about temperature so B is invalid.
suspended
solids.
B a lower temperature
NaCl solutions
are neutral
so have no
effect on pH.
C more
dissolved
salt (NaCl)
particles
D a higher concentration of OH– ions
TAKS Objective 5
Motion , Forces
and Energy
Energy
Is defined as the
Ability to do Work
Energy has Two
Types: Kinetic (Energy of Motion)
and
Potential (Stored Energy)
Kinetic Energy
KE = ½ m v
2
Ex: A moving car has
the ability to
do work on the light
pole if it hits it.
Potential Energy
2 possibilities
Gravitational PE Object lifted to some
height
Elastic PE - A
stretched or
compressed object
(spring or rubber
band)
Gravitational Potential Energy or Will
it fall?
GPE = m g h
m is the mass of the
object in Kg,
g is the acceleration
due to gravity which is
9.8 m/s2 on earth and
h is the height in meters
Use the formula page!
PE = mgh
41 What is the
potential energy of
the rock?
A 59,900 joules
m = 95 kg g = 9.8 m/s2
B 64,600
joules
h = 100
m
C 93,100 joules
2 x 100 =
95 D
kg121,600
x 9.8 m/s
joules
93,100 joules C
Law of Conservation of Energy
• Energy can change forms, but
is never created nor destroyed
• Loss in one form = gain in an
another form
• A falling object speeds up as it
falls to the ground; PE
decreases as KE increases.
The KE it has at impact = the
PE it had before it fell.
Example: A falling object speeds up
as it falls to the ground;
PE decreases as KE
increases, the KE it
has at impact with the
ground is equal to the
PE it had before it fell
Energy can be conserved in
Non-Mechanical forms
The chemical energy in a battery
transforms into electrical
energy
Any reaction where more energy
is given off than is used to start
it is Exogonic
An Endogonic reaction absorbs
energy and causes cooling
Electrical Energy Moving electrons in a path is
electricity
• Electrical Potential Difference (v) is measured in Volts
• The rate of moving electric charges, Electric Current (I),
is measured in Amperes
• Resistance or opposition to the movement of the energy
is called Resistance (R).
Circuits – 2 types
• Series circuits are the
most simple.
• One (1) path for the
current to travel.
• Contains an energy
source, a path, and a
load (something for it to
do, like a lamp)
Circuits – 2 types
• Parallel circuits
provide more than
one path for the
current to travel.
• Most circuits are
parallel, since if
one lamp goes
out, the others can
stay lit.
6. Which switches, if opened, will
cause the light bulb to stop
glowing?
F. Q
G.
R
It is the only
H. S
switch in
J. T
series to
both the
battery and
light.
Thermal Energy
A body contains internal KE due to the
motion of its atoms ( they are
constantly wiggling and jiggling)
Thermal Energy is the total internal KE
of a body
Temperature is the average KE of a
body
Heat- Transfer of
Thermal Energy
Three forms of heating:
1. Conduction-direct contact, a
pot heating on a stove (solids)
2. Convection- heating by
circulating fluids, (gas and
liquid) heating from a fireplace
And. . .
3. Radiation – Transfer of
Electromagnetic (E.M.)
Energy
• Objects are heated
when exposed to
infrared radiation
• The suns heats the
earth by sending
infrared radiation
along with other forms
of E.M. energy 3.0 x
108 meters through
empty space
Heat moves by conduction in solids
since the particles are close together
and vibrate. . .
43 Heat
convection occurs in gases and liquids.
Heat convection does not occur in solids
because solids are unable to —
A absorb heat by vibrating
B transfer heat by fluid motion
C emit radiation by reflecting light
D exchange heat by direct contact
Solids do radiate heat to their surroundings
2 The primary way liquids and
gases transmit heat is by the
process of —
F reflection
G conduction
H radiation
J convection
Fluid heat movement
is convection. Fluid
motion occurs in
liquids and gases.
50 A solar heater uses energy from the
sun to heat water. The heater’s panel is
painted black to —
Convection is movement of heat in fluid matter, heat loss
improve
would
be from
a solidemission
exterior
– infrared
Not Gitsradiation
Painting
aF substance
will notofchange
conductivity –
reduce the
heat lossItbywould
convection
currents
That is a G
property
of metals.
have to
be made of a
improve to
absorption
of infrared
different H
substance
change that:
Not Jradiation
J reduce the heater’s conducting properties
Emission is giving off – we want to absorb: Not F
Nuclear Reactions
Fusion occurs when two atoms
combine to form a new element.
The sun produces all of its
energy through fusion.
Two hydrogen atoms combine
to form a Helium atom from the
great gravitational forces and
pressure in the sun’s core
Nuclear Reactions Fission
• Fission is the splitting of
nucleii of large atoms such as
Uranium and Plutonium
• Produces large amounts of
infrared radiation and other
forms of E.M. Energy such
as Gamma Rays
• Currently, it is the main form
of Atomic Energy on Earth
Radiant Energy or
Electromagnetic Energy (EM)
• All radiant energy travels at 3.0 x 108 m/sec
in space
• Velocity of a wave = wavelength x frequency
• Visible light is just one type of EM Energy
All of the forms of radiation given off
Electromagnetic
Spectrum
by vibrating electric charges
Radiation comes in the form
of vibrating or “throbbing
bundles of energy” called
photons
The frequency of the vibrating
electric charges determines
which type and how much
energy will be given off
•
The entire E.M. Spectrum in
order from lowest to highest
frequency
Radio waves: AM and
•
•
•
•
•
•
FM
Microwaves: cooking
Infrared: heat
Visible: (ROYGBV)
Ultraviolet: tanning
Xrays: medical
Gamma:
Waves - Energy carried by
rhythmic disturbances
• Two types:
• 1. E.M. radiation
move through
empty space
• 2. Mechanical
require a medium
(air, water or any
type of matter) for
movement
Waves - 2 Types
All waves have similar properties
• Frequency- the number of vibrations
per second or the speed of the
movement of the vibrating particles
• Amplitude – the size of the movement
of the vibrating particles
• Both are controlled by the disturbance
that created the waves
Velocity of all waves v=f λ
f-frequency and λ is
wavelength (distance
between identical points on
two consecutive waves)
Reflection- bounce off barriers
in regular ways
Refraction- waves can change
direction when speed
changes
Transverse Waves
• In Transverse Waves
particles vibrate at right
angles to the direction
the wave travels.
• Ex. E. M. Waves, waves
on a slinky or rope coil,
ocean waves
Longitudinal or
Compress ional Waves
Vibrating particles move
back and forth along
the direction of the
wave velocity
Parts consist of
compressions and
rarefactions
Ex. Sound Waves
Sound Waves are Compression
Waves
Sound is produced when a
compression is made.
It requires a producer and a medium
to travel through.
The more elastic the object, the
faster sound travels.
Sound acts like other waves
• Echoes are reflected
sound waves
• Sonar uses echoes to
judge distance to
obstructions
• Human hearing is 2020,000 Hz, below 10
Hz is infrasonic, and
above 20,000 Hz is
ultrasonic.
Forces and Motion
• Forces can create changes in
motion (acceleration)
• Deceleration is negative
acceleration
Motion can be described as
• a change in an
object’s position
• Average velocity
(speed) is the change
of position of an
object over time
Velocity Graphs
V = distance
time
• Velocity (v) is
the slope (rise
over run) of a
position (d) vs.
time (t) graph
Distance (m)
Velocity
60
40
Series1
20
Series2
0
1 3 5 7 9 11 13 15
Time (sec)
Acceleration Graphs
Acceleration
Velocity ((m/s)(m)
• Acceleration (a) is
the slope of a
velocity (v) vs. time
(t) graph
• Plotted on a distance
vs. time graph,
acceleration is an
exponential curve
60
40
20
0
1
3
5
7
9
Time (sec)
11
13
15
Acceleration is a change in an objects
velocity (speed or direction)
• When an object’s
speed changes over
time it is accelerating
(or decelerating)
• A = vfinal – vinitial
time
• Units for acceleration
m/s/s or m/s2
Definition of a Force
• A Force is a
push or a pull
Balanced Force
• A force that
produces no
change in an
object’s motion
because it is
balanced by an
equal, opposite
force.
Unbalanced
Forces
Are forces
that results
in an
object’s
motion
being
changed.
+
Friction
A force that acts in a
direction opposite to the
motion of two surfaces in
contact with each other.
Friction
Friction causes an
object to slow
down and stop.
Since the amount of
energy stays
constant, the
energy becomes
heat.
Newton’s 1st Law of
Motion
• Object in
motion
stays in
motion
Newton’s 1st Law of
Motion
• And
Objects
at rest
stay at
rest
Newton’s 1st Law of
Motion
• Until they are acted upon by
unbalanced forces.
Inertia or Newtons 1st Law
• Tendency for an
object to stay at
rest or moving in a
straight line at a
constant speed.
• The mass (m
measured in kg) of
an object
determines its
inertia
Newton’s 2nd
Law of Motion
Force = Mass X
Acceleration
F=ma
Weight (pull of gravity) is a
commonly measured force,
calculated by F=mg, g is the
acceleration due to gravity 9.8
m/s2
Newton’s 2nd Law of Motion
The greater the
mass of an
object, the
greater the force
required to
change its
motion.
Newton’s 2nd Law of Motion
• The greater the
acceleration of
an object, the
greater the
force required to
change its
motion.
Newton’s 3rd Law of Motion
• For every
action force
there is an
equal and
opposite
reaction
force.
Newton’s
rd
3
Law of Motion
All forces come
in actionreaction pairs
Ex: feet push
backward on floor,
the floor pushes
forward on feet
Work
• Work: using a force
for a distance
• W=Fxd
• The work done by forces on an object
= changes in energy for that object.
• Work and Energy are measured in
Joules
• 1 Joule=1 Newton • meter
Why use a machine?
• In an ideal (perfect)
machine the work put
into the machine (Win) =
the work put out by that
machine (Wout)
Machines make work easier
• The ideal mechanical advantage
of a machine (IMA) of a machine
is the number of times the output
force is larger than the input force
IMA=Fout/Fin
• A machine can only make this
happen by moving the input force
through a farther distance than the
output force
• Fin • din=Fout • dout
Real Machines use Energy
• No real machine is
100 % efficient. i.e.
none put out more
work than is put in
• Efficiency of a
machine is work
output/work input X
100 %
• Eff = Wout X 100%
W
in
Machines use power
• Power: the rate at which
energy is used (work is
done)
• P=Work/time
• Power is measured in
H.P. or watts
• 1 watt = 1 Joule
1 sec
6 Types of simple machines
• Some Simple
Machines:
• Inclined planes
• Screws
• Pulleys
• Wheel and axle
• Levers
• Wedge
Universal Law of Gravitation
All objects in
the universe
attract each
other by the
force of
gravity
Universal Law of
Gravitation
1) the mass of the object
doing the pulling, and
Gravity varies depending on
two factors:
2) the distance from the center
of that object
On Earth gravity = 9.8 m/s/s
• For every second
that an object falls
its speed increases
by 9.8 m/s