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

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" »

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

Example 2: Find parametric equations for a particle that starts at (0, 3, 0) and moves around a circle as shown in Figure 17.1. The circle has a radius of 3 in the yz-plane, centered at the origin.

Solution: Since the motion is in the yz-plane, we have x = 0 at all times t. Looking at the yz-plane from the positive x-direction, we see motion around a circle of radius 3 in the clockwise direction. Thus, the parametric equations are:

• x = 0
• y = 3cos(t)
• z = -3sin(t)

Example 3: Describe in words the motion given parametrically by x = cos(t), y = sin(t), z = t.

Solution: The particle's x- and y-coordinates give circular motion in the xy-plane, while the z-coordinate increases steadily. Thus, the particle traces out a rising spiral, like a coiled spring.... Continue reading "Parametric Equations: Lines, Circles, and Motion in 3D Space" »

Vocab. 1

:

• go shopping
• hang out (penjar)
• listen to music
• play computer games
• read a magazine
• surf the net (navegar)
• watch sport on TV
• dull (avorrit)
• enjoyable (agradable)
• exciting
• frustrating
• interesting
• relaxing
• average (mitjana)
• correlation
• less than half (menys de la meitat)
• majority
• minority
• percentage
• survey (enquesta)

Vocab. 2

:

• adventure
• characters (personatges)
• context
• fantasy
• legend
• myth (mite)
• plot (trama)
• scene
• science fiction
• sript (guió)
• story
• tale (conte)
• angry
• comical
• courageous
• cowardly
• resourceful (ingeniós)
• sentimental
• spiteful (malèvol)
• genre
• metaphore
• moral
• setting (configuració)
• simile
• synopsis
• check over (revisar)
• come to
• come up with (presentar)
• work at
• go back to
• get across
• turn over (entregar)
• write down (apuntar-se)
• carefully
• completely
• convincingly
• daringly (atrevidament)

What is Matter?

Matter is the ‘element’ from which everything is made. It is any substance that has mass and takes up space by having volume.

Where Does Matter Come From?

A billionth of a second after the Big Bang, an important part of the symmetry of the universe was broken. Known as electroweak symmetry breaking, this was the moment when subatomic particles acquired mass for the first time.

What Processes Lead to the Creation of Matter?

A billionth of a second after the Big Bang, electroweak symmetry breaking occurred, and subatomic particles acquired mass for the first time. Among these particles were quarks. As the universe cooled, these quarks combined to form larger, more complex structures: protons and neutrons. Way before the universe... Continue reading "The Origin and Abundance of Matter in the Universe" »

Review

1 Balancing Moments

• seesaw: sube y baja 4
• Perpendicular: At a 90 degree angle to something
• Newton: The unit of measurement of force
• Clockwise: In the same direction as the movement of the hands on a clock
• Counterclockwise: In the opposite direction to the movement of the hands on a clock

Diagram

• a-You have to calculate the moment
• b-The wheel turns more easily when you spin it from near the rim. The distance

M=fd
F=30N
M=fd

Left is 2FI, same result
d=15cm
M=(30) (0.15)=4.5

Right is 2dF, same result
0.15m
M=4.5Nm

2 Making a Scale

• Spring constant: A measure of how stiff or strong a spring is
• Extension: The increase in the length of something
• Elastic: A material able to resume its original shape after being stretched or compressed
• Elastic Limit: The extent to