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

Modern Physics

This branch of physics considers the theory of relativity and quantum theory in describing microscopic systems like atoms.

Model of Modern Physics

In the late nineteenth century, it was a common belief that all phenomena of nature could be described by Newton's laws, principles of thermodynamics, and the laws of electromagnetism, which were based on a mechanical conception of the universe.

Reaffirmation of Modern Physics

In 1905, Albert Einstein produced a series of works that revolutionized physics, mainly due to the wave-particle duality of light and the theory of relativity, among others.

Classification of Modern Physics

It is generally known to study phenomena that occur at the speed of light or values close to it, or whose spatial... Continue reading "Modern Physics: Relativity, Quantum Mechanics, and Nuclear Processes" »

Understanding Geospatial Concepts

Geographical Coordinates

The geographic coordinate system determines all positions on the Earth's surface using two angular coordinates of a spherical coordinate system, which is aligned with the Earth's axis of rotation. It defines two angles measured from the center of the Earth:

• Latitude: Measures the angle between any point and the Equator. Lines of latitude are called parallels and are circles parallel to the Earth's surface.
• Longitude: Measures the angle along the Equator from anywhere on Earth. In most modern societies, Greenwich, London, is accepted as the 0° longitude. Lines of longitude are great circles passing through the poles and are called meridians.

Aerial Photography (Photogrammetry)

Photogrammetry... Continue reading "Essential Geospatial and Mapping Concepts" »

Wireless Access Technologies

FDMA (Frequency Division Multiple Access)

FDMA separates the spectrum into multiple voice channels by dividing the bandwidth into uniform frequency segments. FDMA is mostly used for analog transmission. This technology is not recommended for digital transmissions, even though it is capable of carrying digital information.

TDMA (Time Division Multiple Access)

TDMA technology compresses digital conversations and sends each one with the radio signal for only a third of the time. The compression of the voice signal is possible because digital information can be reduced in size using binary information (ones and zeros).

CDMA (Code Division Multiple Access)

CDMA technology, after scanning the information, transmits it through... Continue reading "Wireless Access Technologies and Signal Propagation" »

Work and Power in Physics

Work acts on a body when a force moves it through a distance; we say that force has done a job. Therefore, the work will be calculated as: W = F · s. The work unit in the SI is the Joule (J), which is defined as the work performed by applying a force of 1 Newton over 1 meter (1J = 1N · 1m).

Conditions for No Work

No work is done when:

• 1. There is no displacement (space is 0); the work is zero.
• 2. The force and displacement are perpendicular (90°).

Power and Efficiency

Power: The quantity that relates work over time; therefore, P = W / t. The SI unit is the Watt (W), defined as work performed at 1 Joule per second (1W = 1J / 1s). It can also be expressed as: P = F · v.

Efficiency: The performance of a machine is never 100%... Continue reading "Fundamental Principles of Work, Power, and Energy" »

Force Interactions

Strength: Action of one body on another, or interaction. Net force (resultant) is the vector sum of all forces acting simultaneously on the same body.

Like acceleration and speed, force is a vector quantity, defined by its magnitude and direction.

Force Measurement

To combine forces on a body, add them vectorially. The net force is equivalent to a single force producing the same effect.

Special Forces

Weight

Weight is the gravitational force a planet or star exerts on a body.

Normal Force

The normal force is a contact force preventing an object from passing through a surface, always perpendicular to it.

Friction Force

Friction force is exerted between two surfaces in contact. Its magnitude on solids depends on surface roughness.

F_r =

1. Energy Transmission at a Distance

Energy can be transferred from one body to another. There are processes that transmit energy even when bodies are separated, such as the emission of sound or light.

Sound

Sound is a mechanical vibration that propagates through material media. For example, the noise from a truck can cause a distant window to vibrate.

Light

Light is radiant energy consisting of particles called photons that propagate through a vacuum and transparent materials like air and water. Sunlight travels through the vacuum of space, heating the Earth after traversing 150 million kilometers.

This form of energy propagation is often referred to as sound waves and light waves. Optics and acoustics are the two branches of physics responsible... Continue reading "Understanding Energy Transmission: Sound and Light Physics" »

Fundamentals of Hydrostatics

Hydrostatics is the branch of fluid mechanics that studies fluids at rest.

Key Concepts and Definitions

Fluid

A fluid is a substance that flows easily and changes its shape under the action of low-magnitude forces. Fluids include both liquids and gases.

• Gases: Molecules vibrate randomly and are compressible.
• Liquids: Take the shape of their container; their vibrating molecules are separated.

Pressure

Pressure (measured in Pascals, Pa, or N/m²) is the quotient resulting from dividing the value of a force acting perpendicularly on a surface by the area over which it is exerted.

• The greater the force, the greater the pressure.
• The greater the area, the lower the pressure.

Any body immersed in a fluid experiences pressure, which... Continue reading "Fundamental Principles of Hydrostatics and Fluid Pressure" »

Forces and Motion

An outside influence that changes a body's state of rest or motion is called force.

Types of Forces

Normal Force: The force perpendicular to a surface exerted on a body by that surface.

Friction: A force resulting from physical contact between a body and its surroundings, opposing motion.

Gravity: A force proportional to acceleration, attracting objects with mass towards each other.

Fundamental Forces: Gravity, Electromagnetic, Strong Nuclear, and Weak Nuclear.

Newton's Third Law

Also known as the Law of Action and Reaction.

Inertial Reference Frame

A frame where a body moves with constant speed if no force acts on it.

Work and Momentum

Work

A scalar quantity obtained from the product of force and displacement.

Momentum

Define this formula:... Continue reading "Physics Fundamentals: Forces, Motion, and Vectors" »

Physics and Chemistry

The scientific method is the process used to investigate natural phenomena. It involves observation, research, hypothesis formulation, experimentation, result interpretation, law formulation, theory and model development, and finally, a scientific report.

Magnitude: A measurable quantity. A crucial magnitude is defined independently; a derived magnitude is defined from other key magnitudes.

Measurement: Comparing a quantity with a unit. The result is often expressed numerically.

Unit: A standard quantity used for comparison. Units must be constant, universal, and reproducible. The International System of Units (SI) is an agreed-upon system.

Accuracy: The smallest variation a tool can measure.

Substance: Anything that has... Continue reading "Physics and Chemistry Fundamentals" »