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

Understanding Physical Forces

A force is the interaction of a body with something external to it and is capable of:

• Modifying its state of motion or rest (we will focus on it).
• Causing deformation.

The Normal Force

The normal force (N) is a reaction force; it is a force resulting from the application of Newton’s third law, which must have exactly the value required for the net force along its axis to be null.

Newton’s Laws of Motion

Newton’s First Law

Newton’s first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This tendency to resist changes in a state of motion is inertia.

Newton’s Second Law

Newton's second law of motion can... Continue reading "Fundamental Principles of Forces and Motion" »

Space Vocabulary

Here are some common space-related terms and their definitions:

• Satellite: A man-made object intentionally placed into orbit.
• Atmosphere: The gases surrounding a planet.
• Gravity: The force that attracts a body toward the center of the Earth, or toward any other physical body having mass.
• Capsule: A small, detachable compartment of a spacecraft.
• Cosmonaut: A Russian astronaut.
• Orbited: Moved in a circular path around a celestial body.
• Re-entering: Returning to the Earth's atmosphere.
• Spacecraft: A vehicle designed for travel in space.
• Touchdown: The moment when an aircraft or spacecraft lands.
• Mission: An important assignment carried out for political, religious, or commercial purposes, typically involving travel.
• Space Shuttle: A reusable

Permanent Magnet

: once magnetized, remains magnetized. Ferromagnet: easily magnetized (iron, nickel, cobalt, some rare-earth metals, magnetite). Paramagnet: magnetized with more difficulty. Diamagnet: repels magnetic fields (slightly) - “not magnetic”./Materials can be broken into smaller chunks, called “domains”. Each domain has a miniature magnetic field. Materials may look the same, but at a smaller level, domains could be different - hence why some are magnets (or magnetize easily) and some don’t. Material, Temperature, Condition, Size & Shape*, Distance, affects magnet strength. All magnets* have two poles; North and South. At poles magnet is at its strongest (repelling or attracting). Breaking a magnet turns into 2 smaller... Continue reading "Understanding Magnetism, Electricity, and Light: A Comprehensive Overview" »

Planetary Systems and the Solar System

A planetary system is a set of gravitationally bound non-stellar objects in orbit around a star. A planet is a non-stellar object in orbit around a star. The barycenter is the center of mass of two or more bodies orbiting each other.

The Eight Planets and Other Bodies

The solar system consists of eight planets, their moons, asteroids, comets, and other minor bodies. The eight planets are:

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

Only five of these planets are visible to the naked eye. Pluto is classified as a dwarf planet or planetoid.

The Solar System Structure

The Solar System is the gravitationally bound system comprising the Sun and the objects that orbit it, either directly or indirectly. Of those... Continue reading "Solar System Mechanics and Planetary Classification" »

Parabolic Motion

Is when an object has two dimensions: U.R.M on the horizontal axis and U.A.R.M on the vertical axis.

Vertical Motion

Is when we throw an object totally up, meaning that the initial velocity or force is only applied in the vertical axis.

Uniform Rectilinear Motion (U.R.M)

Is when an object travels in a straight line at a constant speed with zero acceleration.

Uniformly Accelerated Rectilinear Motion (U.A.R.M)

Is when an object travels in a straight line with constant acceleration.

Inertia

Property of objects to maintain their current state.

Law of Conservation of Matter

Energy is neither created nor destroyed, only transformed.

Gravitational Acceleration

Type of acceleration that attracts bodies towards the center of an astro.

Work

Scalar... Continue reading "Laws of Motion and Gravitation in Physics" »

1) What reason does Michael give for choosing the company where he works?

1. TD principles

Fundamentals of HVAC Duct Systems

• Pressure Measurement: Duct system pressure is measured in inches of water column (in. WC).
• Blower Function: The blower creates pressure to force air through the duct system, conditioning equipment, and into the room.
• Atmospheric Pressure: Standard atmospheric pressure is 14.696 psi.
• Manometer Usage: A manometer measures air velocity pressure in a duct.
• Airflow Measurement Tools: Anemometers or velometers are commonly used to measure airflow in air distribution systems.
• Airflow Check: Airflow can be checked by feeling it 2-3 feet from a register.
• Forced-Air vs. Natural-Draft: Forced-air systems use a blower, unlike natural-draft systems.
• Duct Pressure Components: Duct pressure equals velocity pressure plus static pressure.

Electricity

The smallest part in which matter can be divided is the atom. Its construction is like this:

Nucleus: protons - mass and positive charge / neutrons - mass and negative charge

Orbits of electrons: they do not have mass but they have negative electric charge

Electric charge is a property of subatomic particles which influences the action of forces between items.

Charges of the same sign repel each other / Charges of different signs attract each other

1 coulomb = 6.25x10^18 electrons / The atoms of an object can lose electrons and become charged / The atoms of an object can gain electrons and become charged / Electric current is the flow of electrons through a conductor material

An Electric Device

1) An electric device has a resistance of

Core Concepts of Motion & Force

Understanding Motion

Motion

Change in position relative to a reference point.

Frame of Reference

A system for specifying the precise location of objects in space and time.

Displacement

The change in position of an object. Always includes direction.

Speed

The distance traveled divided by the time interval during which the motion occurs.

Velocity

The speed of an object in a particular direction.

Acceleration

The rate at which velocity changes.

Forces and Their Effects

Force

Any action that can change the state of motion of an object.

Friction

An unbalanced force that acts against an object's direction of motion.

Static Friction

The force that resists the initiation of sliding motion between two surfaces that are in contact at