AHSGE Review for Science

From Passing the Alabama Graduation Exam in Science from The

American Book Company

Scientific Process• Analysis - separation of parts or facts to determine their relationship to

each other

• Assimilation - process of gathering facts and information about an event or phenomenon for the purpose of understanding it

• Conclusion - judgement or inference made based on observation and experimentation

• Control Group - situation maintained in an experiment in which no variable conditions are introduced

• Data - collection of observed and measurable results

• Deductive reasoning - using a generalization that can test a hypothesis or theory to deduce or predict a specific event or phenomenon

Scientific Process cont.• Experiment - process designed to yield measurable results about a hypothesis

under carefully controlled conditions• Experimental Group - selected variable conditions for experimentation to

support or reject a hypothesis• Hypothesis - possible explanation or educated guess given as a solution to a

problem• Inductive reasoning - using specific observations and measurements to enable a

scientist to arrive at a generalized explanation of a scientific problem which can be expressed as a hypothesis or theory

• Observation - noticing an event or phenomenon and gathering facts about it without manipulation of the evidence

• Prediction - to forecast an event or to anticipate the results of an experiment

Scientific Process cont.• Results - the end product of an investigation or experiment

• Science - an exact study by which we acquire knowledge of the universe

• Scientific Process - method of investigation which follows logical steps in problem solving

• Theory - complete explanation of how or why something happens based on research and testing

• Tables are good ways to organize data

• Line graph are best used to show how one variable changes with respect to another

• Bar graphs are used to show easy-to-read, unconnected, bars which represent a quantity of information

• Circle graphs are used to show parts of a whole

Steps to the Scientific Method

• 1. Define or state a problem

• 2. State a hypothesis

• 3. Perform an experiment

• 4. Collect data from experiment

• 5. Draw a conclusion for results

• 6. Make predictions about similar situations in the future

Atoms and Elements• Atom - smallest part of an element composed of electrons (e-),

neutrons (no), and protons (p+)• Electron shell - energy level where electrons are found in

concentration as they move around the nucleus• Element - atoms that have the same number of protons in the

nucleus• Ion - electrically charged atoms (loses or gains e-)• Metalloids - elements that have properties of both metals and

nonmetals (touching zigzag line)• Molecules - chemically bonded group of atoms (act as unit)• Metals - have luster, good conductors of heat and electricity,

and have one to three electron is outer shell (left of zigzag)

Atoms and Elements cont.• Noble gases - elements in the last column of the

periodic chart that are stable and unreactive (gases at room temp)

• Nonmetals - outer energy shell contains more than four electrons and they are dull in appearance and do not conduct heat well (right of the zigzag line)

• Nucleus - central portion of an atom containing no and p+

• Radiation - transfer of energy by waves as particles are released from a decaying nucleus

Structure of the Atom• Atomic Theory - states that all matter is made

up of tiny particles called atoms

• Octet rule - states that the outer shell of electrons cannot hold more that eight electrons

• Valence electrons - number of electrons in outer shell of an atom (1, 2, 3, 4, 5, 6, 7, 8)

• Oxidation number - tells how many electrons an atom gives or takes when it reacts (+1, +2, +3, +/-4, -3, -2, -1, 0)

Elements• The number of p+ in an atom gives the atom its identity• If the number of protons changes, the element changes• Elements on the periodic chart are arranged according to their

atomic number (# of p+)• When you add p+ plus no, it is equal to the atomic mass or

mass number• Atoms of the same element do not always have the same

number of neutrons (isotopes)• In metals, reactivity increase the further left and down you go

in the chart (most reactive metal if francium)• In nonmetals, reactivity increases the further right and up you

go (most reactive nonmetal is fluorine)

Elements cont.

• The first column of elements are the Alkali Metals

• The second column are the Alkaline Earth Metals

• The next to last column are the Halogens

• The small columns in the middle are the transition metals

• The two bottom rows are the Actinide and Lanthanide Series (rare earth elements)

Radioactive Elements

• Alpha particles - 2 p+ and 2 no; have a positive charge; low in energy; can be stopped by a piece of paper

• Beta particles - 1 e-; negative charge; medium energy; 1cm of lead can stop

• Gamma rays - wave of energy; no charge, high energy, thick lead or thicker concrete can stop

Bonding of Atoms

• Ionic bond - results from transfer of electrons from one atom to another; very strong bonds; high melting and boiling points; usually solids at room temp.; usually between a metal and nonmetal

• Covalent bond - formed when two or more elements share electrons to create a more stable outer electron structure; weaker bonds; low melting and boiling points; between two or more nonmetals; diatomic molecules form these

Physical and Chemical Changes in Matter

• Catalyst - substance which speed up a chemical reaction without being used up in process

• Chemical change - rearrangement of the atoms within substances to form a product totally different from the original substance(energy is taken in or given off)

• Physical change - change in form or state of matter in which the molecular structure of a substance remains unchanged while the appearance may be altered (most common is phase changes of matter)

• Products - substances produced at the end of a chemical reaction• Reactants - starting substances in a chemical reaction

Physical and Chemical Changes in Matter

• Surface area - the exposed area of a substance involved in a chemical change

• Temperature - the degree of average kinetic energy within a substance which is measured as heat

• The Law of Conservation of Matter - states that in a physical or chemical change, matter is neither created or destroyed

Chemical Changes

• Combustion - a chemical process in which light and heat are produced

• Fermentation - a chemical change in which a partial breakdown of substances occurs without the presence of oxygen

• Electrolysis - the decomposition of a compound into simpler substances by passing an electric current through the compound

Rates of Chemical Reactions

• The addition of a catalyst to a reaction will cause the reaction to speed up (in the end, the catalyst can be recovered without having been changed)

• The greater the surface area of the reactant substances, the faster the reaction between two substances will take place

States of Matter

• Physical Characteristics of Matter are identifying characteristics of matter such as: color, odor, feel, shape, solubility, hardness, mass, weight, and taste

• Chemical Characteristics of Matter are identifying characteristics of matter such as: atomic structure, density of atoms within matter, and molecular bonds

States of Matter cont.

• Gas - has no definite shape and no definite volume (fills any container)

• Liquid - has definite volume and no definite shape (takes shape of container)

• Solid - has a definite shape and volume

• Matter - a substance existing alone or in some combination

Characteristics of Liquids

• Viscosity - resistance of a liquid to flow

• Surface tension - tendency of a liquid to form a “skin” on the surface

• Cohesion - attraction between particles of the same substance

• Adhesion - attraction between particles of different substances

Characteristics of Solids• Malleable - can be hammered into thin sheets

• Ductile - can be drawn into a wire

• Elasticity - can be stretched or bent and returned to its original shape

• Brittleness - the ease with which a solid breaks when hammered

• Hardness - is the ability of a solid to resist being scratched

• Tensile strength - is the resistance of a solid to break under tension

Transfer of Matter and Energy Through Biological Systems

• Autotrophs/producers - produce their own food through photosynthesis

• Heterotrophs/consumers - depend on others for food• Biotic - living things in an ecosystem• Abiotic - nonliving things in an ecosystem• Biological Systems - living organisms which interact with their

environment and perform functions necessary for life• Cellular Respiration - series of chemical changes within a cell in

which sugar is broken down, oxygen is used, energy is released, and water and carbon dioxide are produced

Transfer of Matter and Energy Through Biological Systems

• Decomposers - help to break down and decompose dead organisms and the wastes of living organisms (fungi & bacteria)

• Energy - inner cellular power within an organism to carry on activities necessary to live

• Energy Pyramid - the transfer through feeding levels of a food chain from producers to various numbers of consumers

• Food Chain - flow of energy and organic material in which the lowest organisms become food for the next highest organisms

• Food Web - all the interconnecting food chains in an ecosystem

Transfer of Matter and Energy Through Biological Systems

• Matter - anything that takes up space• Nutrients - materials needed by the cell to live and grow• Photosynthesis - the process in which a plant makes food

from water and carbon dioxide using energy from the sun• Herbivores - animals that eat only plants• Omnivores - animals that eat both plants and other animals• Carnivores - animals that eat only other animals

• Photosynthesis: 6CO2 + 6H2O C6H12O6 + 6O2

• Respiration: C6H12O6 + 6O2 6CO2 + 6H2O + energy

Diversity of Life• Aerobes - organisms that use oxygen to break down food and

release energy• Anaerobes - organisms that do not use oxygen to break down

food and release energy• Binomial Nomenclature - a system developed by Linnaeus

for naming living things (Homo sapien or Homo sapien)• Parasites - organisms that live on or in another organism and

are harmful to that organism• Plankton - organisms that float on or near the surface of the

ocean• Saprophytes - organisms that feed on dead matter• Taxonomy - the science of classifying living things

Taxonomy• Living things are classified according to their evolutionary

relationships (structure, chemistry, similarities, development, behavior, nutritional needs, methods of obtaining food, and DNA)

• Kingdom is the most inclusive classification and species is the least inclusive Ex.

• King Kingdom Animalia• Phillip Phylum Chordata• Came Class Mammalia• Over Order Primates• For Family Hominidae• Good Genus Homo• Sport Species sapien

Monera Kingdom• Single prokaryotic cell with a cell membrane and a cell

wall like plants

• Have no membrane-bound organelles or nucleus

• Some contain chlorophyll

• Live in damp places or in water and reproduce by asexual fission

• Two phylum of monerans: bacteria and cyanobacteria

• Viruses are often included in this kingdom

Protist Kingdom• Protists can be single-celled or multicellular

• All protists have a nucleus (eukaryotic)

• Some have chlorophyll

• They can be plantlike (euglenas, diatoms, dioflagellates, and algae), animal-like (ciliates, flagellates, sarcodinas, and sporozoa), and fungus-like (molds, mildews, and rusts)

Fungi Kingdom• Fungi are saprophytes (parasites)• Have cell walls• Multicellular organisms that are heterotrophic• The body of a fungus, the mycelium, is a mass of thread-like

tubes called hyphae that grow underground• Reproduce by spores or by budding• Like warm, moist places• Include zygote fungi, sac fungi, club fungi, imperfect fungi,

and lichens

Plant Kingdom• Angiosperm - flowering plants which develop their seeds in a fruit or

protective structure• Chlorophyll - green pigment in plants necessary for the process of

photosynthesis• Deciduous - a broad-leafed plant which loses its leaves in late autumn• Evergreen - plant which sheds its leaves and grows new ones

continuously throughout the year• Gymnosperm - cone-bearing plants which develop their seeds

without a protective covering• Herbaceous - plant with a soft green stem• Nonvascular - lacking connective or supporting tissue• Vascular - network of connected conducting tubes within some

plants• Woody - hard fibrous stem which supports the structure of plants

Plant Kingdom cont.• Multicellular organisms with specialized tissues• Have an organized structure consisting of roots, stems, and leaves• Autotropic• Contain chlorophyll• Have a cell wall• Need water, carbon dioxide, and sunlight to produce sugar and

release oxygen• Bryophytes: Non-vascular spore producing plants• Tracheophytes: Vascular plants

Basic Parts of a Flower

• Stamen - the male structure of the flower

• Pistil - the female structure of the flower

• Anther - produces pollen

• Ovary - produces the ovule

• Stigma - traps the pollen

• Style - the tube from the stigma to the ovary

Animal Kingdom• Invertebrates - animals without a backbone or

internal skeleton; account for 90% of all animals (porifera, cnidarians, worms, mollusks, echinoderms, anthropods)

• Vertebrates - more highly developed with small flexible bones along their dorsal side encasing the nerve cord (chordata)

• External features - outside appearance• Internal features - specialized parts of each

phylum are more highly developed than the previous phylum

Animal Kingdom cont.• All are multicellular (cells form tissues and tissues form

organs and organs make up organ systems)• All are heterotrophic• They grow, reproduce, and develop from larva or embryos• They are free moving at some stage of their development• Respond to their environments and are capable of

complex reactions to environmental stimuli• As animal systems become more complex, the organ

systems are more highly developed and specialized

Systems Found in Organisms• Digestive System - take food into the body and break it down

(mouth, esophagus, stomach, intestines, anus)• Circulatory System - carry food and oxygen to all the cells of

the organism (heart, arteries, veins, capillaries)

• Respiratory System - supply the body cells with O2 and eliminate CO2 (trachea, bronchi, lungs, alveoli)

• Excretory System - remove excess H2O and waste products from the organism (cells, veins, kidneys, skin)

• Nervous System - detect and respond to stimuli in the environment, controls and coordinates body movement and body processes (brain, spinal cord, nerve cells, ganglia, sense organs)

Systems Found in Organisms cont.

• Muscular System - responsible for body movement (muscle tissues or cells)

• Reproductive System - produce eggs and sperm and contain developing embryo (testes, ovary, uterus)

• Skeletal System - work together to provide support for the body (bones, cartilage, ligaments, chitin)

Cells• Active transport - movement of substances through a membrane with the use of

energy • Cell - the unit of structure, function, and development• Chromatin - the substance of which chromosomes are made: proteins, DNA,

and RNA• Endocytosis - a type of active transport that imports particles or small cells into a

cell• Eukaryotic cells - having a true nucleus with a nuclear membrane and organelles• Exocytosis - a form of active transport by which cells move molecules, particles,

or other cells contained in vesicles across the plasma membrane to the cell’s environment

Cells cont. • Gametes - a reproductive cell that contains half the normal

number of chromosomes; a sperm or egg cell

• Homologous chromosomes - pair of chromosomes that resemble each other in length, shape, and the genes they carry (one from mother and other from father)

• Meiosis - type of cell division that results in two daughter cells, each with half the number of chromosomes of the parent

• Mitosis - type of cell division that results in two daughter cells that have the same number and kind of chromosomes as the mother cell

Cells cont.• Multicellular - an organism that is composed of more than one cell with

each cell having a particular function unique to the well-being of the organism

• Organelles - parts of the cell whose function are to contribute to the nourishment, function, and development of the entire cell

• Passive transport - movement of substances into and out of a cell without the use of energy

• Plasma membrane - selective permeable, molecular boundary that separates the cytoplasm of a cell from the external environment

• Prokaryotic cells - have no organized membrane between DNA and cytoplasm and no true organelles

Cell Organelles• Nucleus - control center of cell; storage of hereditary information

• Endoplasmic reticulum - system of folded membrane in cytoplasm; protein synthesis and distribution of materials throughout the cell

• Ribosomes - round-shaped structures in the cytoplasm; sites of protein synthesis

• Mitochondria - powerhouse of the cell, rod-shaped; chemical energy conversions for cell metabolism

• Plastids (plants only) - structures that contain chloroplasts; conversion of light energy into chemical energy, store food

• Golgi complex - flattened membrane sacs; synthesis, packaging, and distribution of materials in the cell

Cell Organelles cont.• Lysosomes - type of storage vesicle; digestion, waste removal• Microbodies - membranes containing enzymes; chemical

conversions of fats to carbohydrates, discharge of wastes• Vacuoles - spherical vesicle; digestion, storage, and

elimination• Microfilaments and Microtubules - fibers and tubes of

protein; movement of internal cell parts• Cilia and Flagella - short and long extensions of microtubes

from the surface of the cell; locomotion and production of currents that draw in food

• Centrioles - short tubes near the Golgi bodies; necessary for cell reproduction within cells

Passive Transport• Diffusion - move from areas of high concentration to areas of low

concentration• Facilitated diffusion - special diffusion that occurs when carrier-

proteins in the plasma membrane assist in the passage of materials into or out of the cell

• Osmosis - movement of water through a semi-permeable membrane from an area of high water concentration to an area of low water concentration

• Hypotonic solution - when a cell is surrounded by a solution that has smaller concentrations of dissolved substances (swell and burst)

• Hypertonic solution - solution on the outside of the cell is higher concentration than inside the cell (shrivel and die)

• Isotonic solution - equal concentration inside and outside

Active Transport

• Exocytosis - a form of active transport in which a cell discharges materials out of the cell

• Endocytosis - a form of active transport in which a cell imports substances into the cell

Mitosis• Type of cell division which generates two daughter

cells with the identical components of the mother cell• The daughter cells are identical to each other as well

as the parent cell• The daughter cells have the same diploid (2n)

number of chromosomes as the parent• Diploid number is 23 pairs or 46 chromosomes• Diploid cells are known as somatic cells

Stages of Mitosis• Prophase - the nucleus of the cell organizes the chromatin material

into thread-like structures called chromosomes; spindles form between the centrioles

• Metaphase - the chromosomes attached at the center or centromeres line up on the spindle at the center of the cell

• Anaphase - chromosomes separate at the center, and the spindles pull them toward either end of the cell; a nuclear membrane forms around the chromosomes as they disorganize

• Telophase - chromatin again forms from the chromosomes, and a cell membrane grows across the center between the two nuclei

Meiosis• Type of cell division necessary for sexual

reproduction

• Produces four reproductive cells with half the number (haploid) of chromosomes of the mother cell

• Haploid number is 23 single chromosomes

• There are two cell divisions, meiosis I and meiosis II

• Haploid cells are known as reproductive cells

Heredity and Genetics• Allele - alternate forms of a gene carried by an individual• Chromosome - a strand of DNA in the nucleus of a cell along which

genes are located• DNA - deoxyribonucleic acid, coiled double-stranded molecules that

carry the genetic code• Dominant - one genetic trait that expresses itself over a recessive trait• Gene - the basic unit for heredity found encoded on the DNA of a

chromosome• Genetics - the study of the passage of biological information from one

generation to the next

Heredity and Genetics cont.• Heredity - the passing on of characteristic traits from parent to offspring• Meiosis - the process of cell division in which cells are produced that

contain only half the number (n) of chromosomes present in the parent cell• Mutation - a sudden change in the DNA pattern passed on to offspring• Protein synthesis - the process within the cell which combines amino acids• RNA - ribonucleic acid, a single-stranded molecule involved in the

manufacture of proteins by a cell• Recessive - a genetic trait that is suppressed in the presence of a dominant

allele

Genetic Expression

• Alternate forms of a gene are called alleles

• Genes can be dominant or recessive

• Dominant traits show up over recessive ones

• The combination of alleles is the genotype (RR or Rr or rr)

• The appearance of the trait is the phenotype (round or wrinkled)

• If you have two like alleles then homozygous

• If two different alleles then heterozygous

Punnett Square

• Used to express the possible combinations for a certain trait an offspring may inherit from the parents (shows genotypes)

• T t

• T TT Tt 1:2:1 Ratio

• t Tt tt 25% homozygous tall

• 50% heterozygous tall

• 25% short

DNA

• The longs strands of DNA are made up of sugars and phosphates

• Short strands are nitrogen-containing structures called bases (adenine, thymine, guanine, and cytosine)

• Adenine and thymine always pair up

• Guanine and cytosine always pair up

DNA cont.

• Replication - the process of making an exact copy of DNA

• Transcription - the process of making messenger RNA

• Translation - the process in which transfer RNA picks up and carries amino acids to the messenger RNA at the ribosomes

Genetic Mutations• Mistakes in the duplication of the chromatin material are called mutations• Take place in the nucleus of the cell during the replication process during

cell division• Most are harmful to an organism, few are beneficial• Gene mutations - mistakes that affect individual genes on a chromosome• Chromosomal mutations - mistakes that affect the whole chromosome• Mutations in the somatic cells (non-reproductive cells) affect only the

tissues of the organism• Mutations in the reproductive cells may be transmitted to the gametes

formed in meiosis and passed to offspring

Causes of Mutations• Radiation exposure can alter sex cells in humans,

which directly affect the offspring by increasing the number of mutations

• Natural mutation-causing chemicals in food and human-made chemicals and pollutants can cause mutations

• Extremely high temperatures can cause mutations

• Some kinds of viruses can cause mutations

Diseases and Disorders• Hemophilia - a sex-linked inherited condition involving failure of blood

to clot properly; defective gene is on the X chromosome

• Down’s Syndrome - a person that has an extra chromosome that occurred when the DNA replicated at the 21st chromosome; the extra chromosome interferes with the normal growth and development of the heart, brain, eyes, and hands

• Sickle-cell - disease that is an inherited trait in African Americans; it is a result of two recessive genes

• Phenylketonuria (PKU) - an inherited disease resulting from a missing enzyme needed to change amino acid phenylalanine to tyrosine; the phenylalanine builds up in the blood and urine and caused brain damage

Interdependence of Living Organisms

• Adaptation - a process by which an organism or species becomes better suited to a change in its environment

• Communities - the interaction of living things in a given area• Convergent evolution - a process in which unrelated species

developed similar characteristics• Divergent evolution - a process by which many different species

developed from a common ancestor• Ecosystem - an environment made up of biotic and abiotic interactions• Greenhouse Effect - temperature increase due to carbon dioxide

buildup in the atmosphere

Interdependence of Living Organisms cont.

• Pollution - introduction of unwanted or unhealthy materials to an environment

• Population - the number of individuals of a species in a given area

• Biosphere - a very thin zone around the earth where living things are found (contains both biotic & abiotic factors)

• Producers - members of the ecosystem which use abiotic factors to make and store energy (trees, shrubs, bushes, moss)

• Consumers - members of the ecosystem which depend on other members for their food (deer, foxes, mice, spiders)

• Decomposers - feed on dead and decaying organisms to reduce them to the simplest forms (mushrooms, fungi, bacteria)

Interdependence of Living Organisms cont.

• Habitat - the dwelling place where an organism seeks food and shelter

• Niche - an organism’s useful place as a productive member in the community

• Predator -an animal that feeds on other living things

• Prey - the animals that predators eat

Symbiotic Relationships• Commensalism - a symbiotic relationship in

which one member benefits from another, but no harm is done to the host (barnacles on a whale)

• Mutualism -a symbiotic relationship in which two organisms live together in dependency on each other (protozoa live in the human intestines)

• Parasitism - a symbiotic relationship that benefits one organism but harms the other (tapeworms in humans)

Diseases• Pathogens - bacteria that causes disease in humans (tuberculosis, typhus,

cholera)• Antibiotics - used to fight bacterial infections (penicillin)• Viruses - parasites that use the material of the host cell to reproduce;

cannot grow, reproduce, or carry on respiration without a host (common cold, pneumonia, polio, measles, chicken pox, flu, AIDS)

• Vaccines - used to fight viral infections; contain weakened or dead viruses that no longer cause the disease; vaccine caused the body to produce antibodies

• Trichinosis - disease in humans caused by the parasite called trichina worms

Ecosystem and Populations• Ecological succession - occurs when one community slowly replaces

another as the environment changes• Climax community - when a few organism establish themselves and

become the dominant species in the area (prairies or rainforests)• Primary succession - when the plants and animals of an ecosystem

have reached a stable and balanced biotic interaction• Secondary succession - the natural act of reclaiming an area (native

plants will once again reclaim land where crops were raised)• Ecological balance - the relationship between the number of plants

in an ecosystem and the number of animals in the system

Things that change Ecosystems

• Fires• Dams• Mining• Floods• Volcanic eruptions• Dumping chemicals (water pollution)• Acid rain• Air pollution

Transfer of Energy• Amplitude - height of a wave

• Decibel - unit used to measure the intensity of sound

• Energy - ability to do work

• Frequency - number of waves that pass a point in a given unit of time

• Hertz - measure of wave frequency and vibrations abbreviated as Hz (1 Hz is one cycle per second)

• Kinetic energy - energy of motion

• Laser - device that produces a highly concentrated, powerful beam of coherent light which is all one frequency or color

• Photon - particle of radiant wave energy

• Pitch - tone of a sound wave, determined by the frequency of the wave

Transfer of Energy cont.• Potential energy - stored energy

• Prism - transparent material with two straight faces at an angle to each other

• Radiation - process of transfer of heat energy by waves from an area of high temperature to an area of low temperature

• Reflection - bouncing of a wave or ray off a surface

• Refraction - bending of a wave or ray caused by a change in speed as it passes from one substance into another

• Vibration - rapid back and forth movement of matter

• Velocity - speed of matter in a definite direction

• Waves - rhythmic disturbance which travels through space or matter

• Wavelength - distance between peaks of a wave

Transferring of Heat• Heat - the energy transferred between matter as a result of

differences in temperature (increase in temp increases the particle movement and vice versa)

• Conduction - kinetic energy is transferred as particles hit each other (coffee heats up the spoon)

• Convection - in liquids and gases; causes currents which carry heat upward (mirage)

• Radiation - transfer of heat energy by waves in space (fireplace)• Conductors - substances through which heat energy is allowed

to transfer quickly• Insulators - slow the transfer of heat

Waves• Transverse waves - up and down movements in which

the motion of the medium is at right angles to the direction of the wave (water and light waves)

• Longitudinal or Compression waves - a series of pushes in which the motion of the medium is parallel to the direction of the wave (sound waves)

• Long wavelength has low frequency and low energy• Short wavelength has high frequency and high energy

Earthquake Waves• Primary (P) waves - compressional waves that move in

push-pull motions similar to sound waves; travel through the earth and can pass through solids, liquids, and gases; fastest and first detected

• Shear (S) waves - called secondary waves; transverse waves that cause rock to shake sideways; travel through earth but only pass through solids; travel about half the speed of P waves

• Long (L) waves - slow-moving waves which travel along the earth’s surface; slowest of all

Force and Motion• Acceleration (m/s2) - change in velocity over time

• Force (N) - push or pull exerted on matter

• Friction - force between surfaces that opposes motion

• Gravity - force of attraction between any two objects that have mass

• Inertia - tendency of an object at rest or in motion to remain at rest or in motion

• Joule - unit of work equal to one Newton meter

• Machine - device which can affect force or effort

• Motion - change in the position of an object as compared with a reference point

• Newton - unit of force

Force and Motion cont.

• Velocity - speed in a definite direction

• Watt - unit of power equal to one joule per second

• Work (J) - any process in which matter is moved by the action of force

• Force (N) = mass (kg) * acceleration (m/s2)

• Weight (N) = mass (kg) * acceleration (m/s2)

Universal Law of Gravity

• Formulated by Sir Isaac Newton

• Every object in the universe pulls on every other object

• The more mass an object has, the greater its gravitational force

• The greater the distance between two objects, the less attraction they have for each other

Work and Power

• Work is the product of the force applied to an object and the distance the object moves; measured in joules

• work (J) = force (N) * distance (m)

• Power is the work done per unit of time

• power (W) = work (J)/time (s)

Newton’s Laws of Motion• 1st - an object which is moving or at a state of rest does not

change its state of motion unless a force acts on it; Law of Inertia (a ball will roll in a straight line until it hits a wall)

• 2nd - acceleration of an object increases as the amount of force causing the acceleration increases (if you push two carts with the same force, the smaller cart accelerates greater)

• 3rd - for every force, there is an equal and opposite force (when two identical balls traveling at the same speed collide, they change direction)

Pressure

• Only one kind of matter can occupy a given space at a given time

• Pressure - force that acts over a certain area

• If pressure on the outside of an object is equal to the pressure on the inside of an object, then nothing moves (vacuum cleaner lowers pressure inside so it can suck up dirt)

• Suction is a result of unequal air pressure (using a straw to drink coke)