Notes, summaries, assignments, exams, and exercises for Physics for Other courses

Engineering Safety Codes and Standards

Nowadays, the first concern of any engineer is safety. This concern has led to the introduction of worldwide codes and standards for the manufacture and maintenance of machines. Engineers began to understand the science behind the behavior of metals and other materials. The steam engine was one of the first machines which aroused interest in safety standards.

The steam engine works on a very simple scientific principle: when you heat water in a vessel, the molecules expand until, at a certain temperature, the liquid turns into a gas. The American Society of Mechanical Engineers (ASME) produced the Boiler Safety Code. Since then, the ASME has produced codes in all areas of mechanical engineering, including...

The Anthropocentric Perspective and the Geocentric Model

Ideas that placed the human species in the center of the universe are known as the anthropocentric perspective. Overcoming this viewpoint has been a slow and costly process, during which scientists have struggled against prejudices, myths, and superstitions.

Ptolemy and the Geocentric System

Ptolemy created a model of the universe with Earth at the center, around which the Moon, Sun, and other stars revolved. Although subsequently proven incorrect, this geocentric model was accepted for centuries. Over time, the practical observation of the sky became more widespread, increasing the number of astronomers and observatories.

Copernicus and the Heliocentric Revolution

The proposed Ptolemaic system...

Gauss's Law in Electromagnetism

For a closed surface represented by i, the number of electric field lines leaving the surface is equal to the number of lines entering it. This is consistent with the fact that no net charge is enclosed by the surface. However, for the closed surface ii in the same figure, there is a net outward flux, indicating a net positive charge enclosed.

The situation is radically different for magnetic fields, which are continuous and form closed loops. Examine the Gaussian surfaces represented by i or ii. Both cases visually demonstrate that the number of magnetic field lines leaving the surface is balanced by the number of lines entering it. The net magnetic flux is zero for both surfaces. This is true for any closed surface....

Item 18. Non-ionizing Radiation

Non-ionizing radiation is radiation that is not capable of producing ions when interacting with atoms of a material. It is characterized by low frequency and small photon energy (<1.23 meV).

Main Types

They fall into two main groups:

• Microwave (MW) and radio frequency (RF)
• Visible and near

Public Health Concern

In May 1996, in response to growing concern in many Member States about the potential public health effects of exposure to electric and magnetic fields emitted by increasingly numerous and diverse sources, the World Health Organization launched an international project to assess the health and environmental effects of exposure to these fields. This became known as the International EMF Project.

Units

• Electric

Solubility and Gas Behavior

Solubility is the maximum amount of solute that can dissolve in a given amount of solvent. A solution is saturated when it is not possible to dissolve any more solute.

• The solubility of gases in liquids decreases as temperature increases.
• The solubility of gases in liquids increases with pressure.

Characteristics of Matter

Atmospheric Pressure

Atmospheric pressure is the force exerted by the atmosphere due to its weight on the surface of bodies in contact with it. It is exerted equally in all directions and acts perpendicular to the surface.

• 1 Atmosphere: The pressure exerted

Our Cosmic Address and the Scale of Space

Understanding our place in the universe begins with our Cosmic Address:

• Universe
• Filaments and Voids
• Local Supercluster
• Local Group
• Milky Way Galaxy
• Solar System
• Earth
• Asia

Defining Celestial Objects

• Planet: A rocky, icy, or gaseous object that orbits a star, shining by reflected light. (d_Earth ≈ 0.009d_Sun; d_Jupiter ≈ 0.1d_Sun)
• Satellite: A man-made or natural object that orbits a planet.
• Asteroid: A relatively small and rocky object that orbits a star, often non-spherical in shape.
• Comet: A relatively small and icy object that orbits a star. Comets usually have two tails: a plasma tail and a dust tail.
• Solar System: A star and all the material that orbits it, including its planets and moons.
• Nebula: An interstellar

Mean Free Path in Kinetic Theory

Mean free path is the average distance traveled by a gas molecule between two successive collisions with other molecules.

• It is denoted by the Greek letter λ (lambda).
• It depends on the size of the molecules, pressure, and temperature.
• A higher pressure decreases the mean free path, while a higher temperature generally increases it.
• Formula:
  [ λ = \frac{1}{\sqrt{2}\pi d^2 n} ]
  where d represents the diameter of a molecule and n represents the number of molecules per unit volume.

Gibbs Free Energy and Thermodynamic Stability

Gibbs free energy (G) is the thermodynamic function that indicates the maximum useful work obtainable from a system at constant temperature and pressure.

• It is defined by the equation:
  [ G = H - TS

Basic Quantities and Units

• Mass (m): The amount of matter or a measure of inertia. Unit: kg.
• Weight (W): Gravitational force. Formula: W = mg. Unit: N.
• Force (F): A push or a pull. Unit: Newton (N).
• Speed: Distance divided by time (m/s).
• Velocity (v): Speed plus direction (a vector).
• Acceleration (a): Change in velocity divided by time (m/s²).

Vectors vs Scalars

• Vector: Magnitude and direction (e.g., velocity, acceleration, force, momentum).
• Scalar: Magnitude only (e.g., mass, speed, energy).

Newton’s Laws of Motion

First Law (Inertia)

An object at rest stays at rest, and an object in motion stays in motion unless acted on by a net force.

Second Law

Formula: a = F/m

• More force leads to more acceleration.
• More mass leads to less acceleration.

Third Law

For...

Fundamental Electrical Units

• Current: Ampere (A)
• Voltage: Volt (V)
• Resistance: Ohm (Ω)
• Power: Watt (W)
• Charge: Coulomb (C)

Metric Prefixes

• peta (P): 10^15
• tera (T): 10^12
• giga (G): 10^9
• mega (M): 10^6
• kilo (k): 10^3
• milli (m): 10^-3
• micro (µ): 10^-6
• nano (n): 10^-9
• pico (p): 10^-12
• femto (f): 10^-15

Significant Figures and Math

• Non-zero: Significant
• Leading zeros: Not significant
• Middle zeros: Significant
• Trailing decimals: Significant
• Addition/Subtraction: Match decimal places
• Multiplication/Division: Match significant figures

Core Electrical Concepts

When electrons move, they create current. Current is defined as I = Q/t, and voltage is V = W/Q.

Q represents coulombs (electrical charge). One volt is the potential difference between two points when one joule of energy...

The Modern Scientific Worldview

Until the 19th Century, the scientific process was dominated by the conceptual schemes of Isaac Newton and Galileo Galilei. Many scientists felt they were nearing a point where no significant new laws remained to be discovered. However, two new branches of physics would completely transform our worldview, affecting both the macrocosm and the microcosm: the theory of relativity and quantum physics.

The Theory of Relativity: Revolution in the Macrocosm

Albert Einstein published the theory of special relativity in 1905. It posits that there is no absolute space or time independent of the subject who experiences them. Instead, space and time are relative to speed. Time elapses differently for two observers traveling...