Notes, summaries, assignments, exams, and problems for Physics

Thermodynamics

First Law of Thermodynamics (Law of Energy Conservation)

Energy cannot be created or destroyed; it can only change forms.

Formula: ΔU=Q−W

Where: ΔU is the change in internal energy of the system, Q is the heat added to the system, W is the work done by the system.

Explanation: The total energy in a closed system remains constant. Energy can be transformed from one form to another (e.g., heat energy to mechanical energy).

Second Law of Thermodynamics

Key Concept: The total entropy (disorder) of an isolated system always increases or remains constant.

Formulas:

Entropy Change for Reversible Process: ΔS=Qrev /T

Where: ΔS is the change in entropy. Qrev is the heat added in a reversible process. T is the absolute temperature. Qirr is... Continue reading "Thermodynamics and Simple Harmonic Motion" »

.All material objects are composed of atoms. An atom consists of a nucleus and a vast region of space outside the nucleus. Electrons are present in the region of space outside the nuclues. Electrons are often removed from and a dded to an atom by normal everyday occurrences. The nucleus contains positively-chargedd protons and nuetral neutrons. These prtons and nuentrons are not removable or disturbable by usual everyday methods. One sure truth of this unit is that the porotn and neutron will remain within the nucleus of the atom.
Methods of charging:-friction:Having an excess of electrons thr rubber ballon is charged negatively.The shortage of electrons on the animal fur leaves it with a positive charge.-Induction: is a very common method of... Continue reading "Basic Principles of Electricity and Atomic Physics" »

By: accident, chance, hand, heart, law, mistake, no means, request, virtue of, in a good mood, private, return, time, brief, danger, difficulty, doubt, a hurry, a mess. On: purpose, a regular basis, schedule, strike, time (a tiempo), average, balance, condition, fire. At: a price, one time, risk, the age of, all cost, a glance, least. Of: member, remind, at a rate, a cause, approval, experience, get rid, habit. With: link, regret, sympathize, arguments, contact, concern, dealing, difficulty. To: explain, reply, access, addiction, belong, change, damage. For: life, once, real, a while, a reason, demand, hire. From: time to time, now on, memory, experience. Out: of place, of stock, of sight. Conductance: the amount of power - Conductivity: The... Continue reading "Understanding Energy and Electricity: A Comprehensive Guide" »

FORCE:

George Orwell: A Life of Social and Political Commentary

Early Life and Influences

Born Eric Arthur Blair in 1903 in British-ruled India, George Orwell's life and works were deeply shaped by his experiences. His early exposure to the rigid social hierarchy and hardships of colonial India, as recounted in his autobiographical essay "Such, Such Were the Joys," fueled his later critiques of social stratification and power dynamics. Orwell's education as a scholarship student amongst England's wealthy elite further solidified his understanding of social inequalities, themes that would later emerge in his novels like "Animal Farm."

From Burma to Literary Pursuits

After graduating in 1921, Orwell joined the Indian Imperial Police in Burma. This experience... Continue reading "George Orwell: Life, Works, and Social Commentary" »

What Evidence Do Rocks Provide About Life?

Rocks are still an important source of information about many forms of life that existed on this planet.

Why Can Scientists Not Be Sure How Earth Was Created?

Because no rock dates to the formation of the Earth.

How Might Fossil Teeth Reveal an Animal's Diet?

Size and shape indicate diet.

Explain Relative Dating of Fossils

Sedimentary rocks form layers, with newer or younger layers added on top of older layers. This does not tell scientists the exact age of the fossil; however, it does tell the scientist the fossil's age in relation to others above it or below it.

Two More Common Radioactive Isotopes

• Potassium-40
• Carbon-14

What Is a Mass Extinction?

It is when many organisms disappear from the fossil record at... Continue reading "Unlocking Earth's Secrets: A Guide to Fossils, Geological Time, and the Origin of Life" »

Energy: Forms, Transfers, and Conservation

Energy is a fundamental concept in physics, existing in various forms and constantly undergoing transformations. Understanding these forms, how energy is transferred, and its conservation is crucial.

Energy Stores (Forms of Energy)

• Kinetic Energy: The energy of a moving object (e.g., runners, moving buses).
• Gravitational Potential Energy (GPE): Energy of an object due to its position in a gravitational field, typically its height (e.g., kites, a ball being thrown).
• Chemical Energy: Energy stored in chemical bonds (e.g., muscles, batteries).
• Elastic Potential Energy: Energy stored when an object is stretched or squashed (e.g., an inflated balloon, compressed springs).
• Magnetic Energy: Energy stored when repelling

Understanding Electrical Principles and Circuits

Static Electricity Fundamentals

When an atom becomes an ion, it becomes charged. When two insulating materials are rubbed together (e.g., wool and a plastic rod), electrons move from one material to another (as protons cannot move). This process results in one material becoming negatively charged and the other positively charged. Once charged, these materials can attract uncharged objects and objects with an opposite charge.

Understanding Electrical Sparking

A significant charge builds up on one object due to electrons being rubbed off by another. If a large enough charge accumulates, the voltage becomes sufficiently high to ionize the air molecules. This allows electrons to jump to earth, causing... Continue reading "Electrical Principles: Circuits, Static & Quantities" »

Tema 2

TEMA 2.High middle ages(1001-1300) and late m.A(1300-1485).Ongoing Expansion of islamic faith.Anglo-Sxon england invaded by William ,duke of Normandy.They Took literal possessions.Anglosazon=>Norman->Feudalism.Feudalism:complez social organisation based on functions and jiearchies. Functions: Oratores,bellatores,laboratores.Hierarchical: form superior to inferior According to essential degree.Defining features of the english medieval Period:-Resistance to monarcha´s feudal power.-Instability of political Power.-Pope´s authority also contested(Thomas becket´s murder in Canterbury)-Origin of some genuine institutions(oxford university, cambridge...)-Population Increase+developement of cities as centres of production and Commerce-