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

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1. Stopwatch Accuracy

a) Stopwatch

b) To have more accuracy

c) i) 3rd

ii) (3.93 + 4.07 + 3.99) / 3 = 11.99 / 3 = 4

iii) 4 / 10 = 0.40

2. Water Speed Measurement

a) First, measure the distance between bridge X and bridge Y. Then, place the stick in the water at bridge X and time how long it takes to reach bridge Y. Calculate the speed by dividing the distance by the time. Repeat this process at least three times. Add all the results together and divide by three to get the average speed.

b) 2nd box

3. Acceleration and Force

a) i) 24 / 60 = 0.4 m/s²

ii) 7.5 × 10⁵ × 0.4 = 300,000 N

b) Speeding up / Slowing down / Steady speed / At rest

4. Resultant Force and Density

a) i) 280 - 250 = 30 N

ii) Up

b)... Continue reading "Physics Exam Answers and Explanations" »

Fundamental Concepts in Physics

The Atom

An atom is composed of electrons, protons, and neutrons.

Temperature

Temperature is the physical quantity that describes the sensation of cold or hot, directly related to the average kinetic energy of molecules. It represents the average kinetic energy of each molecule.

Heat

Heat is the transfer of energy from one body to another due to a temperature difference. It is a form of energy that can be perceived through temperature variations.

Types of Thermal Expansion

• Linear Expansion
• Surface Expansion
• Volumetric Expansion

Thermodynamics

Thermodynamics is the branch of physics that studies heat transfer and the conversion of energy into its various forms.

Laws of Thermodynamics

• Zeroth Law
• First Law
• Second Law

Zeroth Law

Electrostatics Fundamentals

This document covers key concepts in electrostatics, including properties of electric charge, Coulomb's Law, and electric fields.

Properties of Electric Charge

Here are four fundamental properties of electric charge:

1. Additivity of Charges: The total charge of a system is the algebraic sum of all individual charges present in the system.
2. Conservation of Charge: The total charge of an isolated system remains unchanged over time. Charge can neither be created nor destroyed, only transferred.
3. Quantization of Charge: The total charge of a body is always an integral multiple of a basic quantum of charge, denoted as 'e'. This means charge q can only exist as q = ±ne, where n is an integer (1, 2, 3, ...).
4. Interaction of Charges:

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" »

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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