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

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

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)

The Genesis of New Criticism

English Foundations: I.A. Richards' Influence

The roots of New Criticism were initially in England, specifically at the University of Cambridge, championed by I.A. Richards. A lecturer, Richards linked New Criticism to the USA by moving to Harvard in 1939. He found in America a very suitable ground to develop his theory of criticism, as Americans sought new methods for literary study without relying on external context. Richards' seminal work, Practical Criticism, explains his method in detail.

René Wellek and Cosmopolitanism

René Wellek contributed significantly to the cosmopolitan component of New Criticism, ensuring it was not an exclusively Anglo-American method of criticism.

American Roots: The Southern Literary

The Rise of New Criticism

The New Critical method was rapidly adopted, particularly in the North, due to its inexpensive and easily transferable characteristics. Prominent scholars in the North included Austin Warren, W.K. Wimsatt, and Cleanth Brooks. Brooks, in particular, emerged as the most influential New Critic.

Transforming Literary Study

Traditionally, English literature was taught as the History of English Literature, an extrinsic method. New Critics sought to transform these departments into centers of Literary Criticism. They achieved this through three key methods that fundamentally changed the organization of the teaching profession:

• Staffing University Departments

  Gradually, New Critics began to occupy chairs of literature previously

Features of English Practical Criticism

The origins were a desire to rescue literary studies from historicism and contextualism, and proponents wanted to turn literary study into a scientific method — to give seriousness and a true methodology to the analysis of literature. Richards thought that the only way to do that was to restrict the study to the text alone.

Richards gave his students sheets of paper on which literary fragments had been printed: short poems or fragments of longer works. He did not print the name of the author, the title, or the date, in order to decontextualize the text for study. He told the students to work with the text with no additional information. From these studies, he wrote Practical Criticism in 1929, from which... Continue reading "Practical Criticism and New Criticism: Principles & Fallacies" »