Notes, abstracts, papers, exams and problems of Physics

ly d la consrvacion d la +a: en cualkier raccion q tnga lugar en 1 sistma crrado, la +a total d ls sustancias s consrva. s dcir la +a d ls ractivos s la misma q la d ls productos. proust: cuando s combinan 2 o +lmntos pa dar 1 dtrminadolmntos lo acn siempr en 1a proxcion fija, con indpndncia d su stado fisico. dalton: 2 o +lmntos puedn combinars entr si  en + d 1a proxcion pa dar compustos distintos. en s caso 1a cantidad prmanc fija y otra varia en 1 proxcion d numros entros. toria atomica: 1.-los elemntos stan formados por particulas pekeñisimas, llamdas atomos. 2.-todos los atomos d un mismo elemnto son = y x tanto tienen la misma masa y propiedades. 3.- los compuestos qimicos estan formado por la union d atomos d diferentes elemntos, y esos atomos s combinan en una relacion d numeros sencillos. 4.+ los atomos ni se crean ni se destruyen n una reaccion qimica unicament s distribuyen.
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In the end, the Galileo spacecraft will get a taste of Jupiter before taking a final plunge into the planet's crushing atmosphere, ending the mission on Sunday, Sept. 21. The team expects the spacecraft to transmit a few hours of science data in real time leading up to impact.

The spacecraft has been purposely put on a collision course with Jupiter to eliminate any chance of an unwanted impact between the spacecraft and Jupiter's moon Europa, which Galileo discovered is likely to have a subsurface ocean. The long-planned impact is necessary now that the onboard propellant is nearly depleted.

Without propellant, the spacecraft would not be able to point its antenna toward Earth or adjust its trajectory, so controlling the spacecraft would no longer be possible.

"It has been a fabulous mission for planetary science, and it is hard to see it come to an end," said Dr. Claudia Alexander, Galileo project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "After traversing almost 3 billion miles and being our watchful eyes and ears around Jupiter, we're keeping our fingers crossed that, even in its final hour, Galileo will still give us new information about Jupiter's environment."
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F= (G m1.m2)/r²

G= GM/r²

Ep= -GMm/r

v= -GM/r

W= m(v1-v2)= Ep1-Ep2

g=go/(1+h/RT)²

V= √GM/R

T= 2πR/v

v= wR

Em= -1/2GMm/R

Ve=√2GM/R

T1²/R1³= T2²/R2³= 4π²/GM

w=√K/m

T=2π√m/k

Ep=1/2kx²

Pendulo: T=2π√L/g      f=1/2π√g/L

vp=λf= λ/T

K= 2π/λ

Ec=1/2 mv²

Ep=1/2ky²

I=Ioeβx

β=Coef de absorcion

x=espesor del medio

I=P/S

I1/I2=R2²/R1²

A1/A2=R2/R1 esferico

A1/A2=√R2/R1 circular

A force: is a push or pull acting upon an object as a result of its interaction with another object.Their effects: they can make an object move, change the speed of it, change the direction, change the shape..  2 types of forces:CONTACT FORCES Frictional ,Tension, Normal, Applied, Spring .ACTION-AT-A DISTANCE FORCES. gravitional, electrical and magnetic.tension: force that a spring or similars exerts on the object in these type of problems. Resistive Forc: prevents the slipping or sliding of 2 surfaces in contact. Normal force: exerted on an object which is in contact to another stable object. NEWTON LAWS

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The cell cycle: sequence of cellular growth and division.
5 phases=
1.First growth(the cell grows.)
2. Synthesis(dna is copied)
3. Second growth(prepares the nucleus to divide)
4. Mitosis(the nucleus divides)
5. Cytokinesis(cytoplasm divides)
CONTROL of the cell cycle during the checkpoints.
1.first growth checkpoint
2. second growth checkpoint
3. mitosis checkpoint
WHEN CONTROL IS LOST=CANCER.


MITOSIS= the chromatids on each chromosomes phsisically moved to opposite poles of the dividing cell helped by the SPINDLE(cell structure made of centrioles and proteins[microtubes}.
PROPHASE=THE NUCLEUS DISOLVES
METAPHASE=chromosomes aling in the equator of the cell.
ANAPHASE=chromatids move toward opposite poles.
Telophase=nuclear envelope forms, cytokinesis occurs.
MEIOSIS= formation of haploid cells. Gametes are haploid cuz they have 1 set of chromosomes.
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Properties of ionic compounds= crystalline solids at room temp, high melting points, conduct an electric current when melted or dissolved in water.
Coordinating number=# of ions of opposite charge that surrounds anions in a crystal.
Bonding in metals= metals are made up of closely packed cations. The valence electrons of metal atoms can be modeled as a sea of electrons(cuz tha valence electrons are mobile and canm drift freely one part of the metal to another)
Metallic bonds= consist of the atraction of the free floating valence electrons in the positively charged ions. The sea of electrons explains many physiscal properties of metals such as(good conductors of electricity,ductile,maleable)


Crystalline structure of metals= metal atoms are arranged in very compact and orderly patterns. 3 arrangements
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Some ions formed by transition metal dont hace noble gases electron configuration, they are EXCEPTIONS TO THE OCTET RULE. their configuration is know as=PSEUDO-NOBLE GASES.
formation of ions= an anion is an atom or group of atoms with a negative charge. The gain of electrons by a neutral atom produces an anion. The goal is to attain noble gas electron configuration but but in this case gainin electrons.
Ions that are produced when halogen atoms gain electrons are called HALID IONS.

Ionic compounds= compounds composed of cations and anions(metal cations & non metal cations). Although they are composed of ions, an ionic compoun is electrically NEUTRAL cuz the total positive charge of the cation equals the total negative charge of an anion.
Ionic bonds=anions and cations have opossiye charges and attract one another by means of electrostatic forces. Those elctrostatic forces are the ionic bonds.
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EXPELENTE, i want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you nowi want to buy the camera from you now

Variety:means differences between individuals.CLONING: we take a somatic cell with 2n.the somatic cell is put in a media to lose its identity.we remove the nucleous of an egg cell.we fused the somatic cell with the eeg cell and through this the somatic cell enters inside the egg cell. we put the final cell inside the another sheep.we will get a clone from the first sheep. Clone: is an individual which has been produced asexually from its parents. Cloning:asexual way of reproduction. Cloning plants:we can produce new plants by taking cuttings from the older plant and them you plant to make possible the growing. Difference between natural and artificial embryio twinwing:natural->in the first step the zygote divides into two identical embryios. Artifical-> in the first step the man separate the zygote and makes two identical embryos. difference of twins:identical->comes from the same egg cell. twins-> comes one from different ovul. How is a gene taken out from one organism to b ... (Continue)

Chapter 1
1. Character's name: Glenda Johnson
2. Where is she? Near the hospital of the little village of Greenview (Rocky Mountains).
3. Why is a helicopter going to the hospital? Because two climbers need medical help.
4. What is “the secret” of White Mountain? People said there is a curse.
Chapter 2
5. Character's names: Ricky, Sandy (brother-sister), Janet, Peter (friends Ricky and Sandy, brother-sister), Mr Noble (shop assistant) .
6. How old are Ricky and Sandy?

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