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

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

Physics Fundamentals: Multiple Choice Questions

1. The SI base unit for mass is:
e. kilogram

2. For which of the following situations is the conservation of mechanical energy most likely to be a valid assumption?
b. a parachutist falls from a plane

3. The slope of a line drawn tangent to a point on the curve of a position versus time graph describes what concept?
c. instantaneous velocity

4. As an object falls towards Earth:
d. the upward acceleration of Earth is negligible because of its large mass

5. Mass differs from weight in that:
b. weight is a force and mass is not

6. The main difference between kinetic energy and potential energy is that:
b. Kinetic energy involves motion, and potential energy involves position

7. A lead ball and a book are

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" »

Define Electric Charge and Basic Properties

Define an electric charge and explain the basic properties of electric charges

Electric charge is a fundamental property of matter associated with an excess or deficit of electrons relative to protons. It is carried by particles such as electrons (negative) and protons (positive). Charge can be transferred between bodies by different modes such as rubbing (friction), induction, conduction, or other specific methods.

Properties

• Additive: net charge is the algebraic sum of individual charges.
• Conserved: total charge in an isolated system remains constant.
• Quantized: charge occurs in integer multiples of the elementary charge (e).

Charging Insulators by Friction and Induction

Explain the process of charging