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

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" »

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

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

Thermal Energy and Matter

Work and Heat

Heat is the transfer of thermal energy from one object to another because of a temperature difference. Heat flows spontaneously from hot objects to cold objects. Temperature is a measure of how hot or cold an object is compared to a reference point. On the Kelvin scale, absolute zero is defined as a temperature of 0 kelvins. As an object heats up, its particles move faster, on average. The average kinetic energy of the particles increases. One way that heat flows is by the transfer of energy in collisions. On average, high-energy particles lose energy. Low-energy particles gain energy.

Thermal Energy

Thermal energy is the total potential and kinetic energy of all the particles in an object and depends on... Continue reading "Thermal Energy and Matter: Heat, Temperature, and Specific Heat" »

Understanding Semantic Roles

Unit 6

The Beer-Lambert Law

The Beer-Lambert law describes the linear relationship between the absorbance of light and the concentration of an absorbing species. The relationship is defined by the formula: A = εlc, where:

• A is the absorbance (unitless).
• ε is the molar absorptivity or extinction coefficient.
• l is the path length of the light through the sample.
• c is the concentration of the absorbing species.

This law establishes a direct correlation between absorbance and concentration under specific conditions, such as using a dilute solution and monochromatic light. It is a fundamental principle used for quantitative analysis in methods like UV-Vis spectroscopy and infrared spectroscopy. In a linear calibration plot where the path length is 1 cm, absorbance... Continue reading "Principles of Beer-Lambert Law and Voltammetry" »