To people who have grown up in the 1930’s and 1940’s, used clothing was associated with the hard times of the Great Depression. For the newer generations, used clothing is a way to find unique, affordable clothing that can stretch the boundaries of mainstream style

we can see that humans everywhere create culture to meet their needs

Human beings have developed flexible biological and social features that have worked together in a wide variety of environmental and historical conditions to produce a diversity of cultures.

To people who have grown up in the 1930’s and 1940’s, used clothing was associated with the hard times of the Great Depression

ethnobotany examines how people in different cultures categorize and use plants for food, shelter, tools, transportation, art, and religion.

the way that all elements of human life interrelate to form distinctive cultures: holism.

Anthropologists study every possible realm of human experience, thought, activity, and organization. Human as we are, we can only engage in social and natural worlds through our human minds and human bodies. Even engagement with nonhuman realms such as astronomy and botany is conditioned by our human senses and human cognition and thus varies across different societies and different time periods.

In many countries, for instance, university students typically wear dress shirts with slacks or skirts to class. Many Ghanaian students would not dream of wearing ripped jeans or tight leggings to class, considering such casual dress disrespectful

This central story and these common commitments hold the discipline together, enabling anthropologists to combine insights from diverse fields into one complex portrait of what it means to be human.

American students put much more emphasis on comfort than on presentation, an overall trend in American dress.

Many Ghanaian students would not dream of wearing ripped jeans or tight leggings to class, considering such casual dress disrespectful.

anthropology is the study of humanity across time and space.

Just as the various parts of our bodies all work together (the brain, the heart, the liver, the skeleton, and so forth), the various parts of a society all work together as well (the economy, the political system, religion, families, etc.)

anthropology is the study of humanity across time and space.

which way is better, the American way or the Ghanaian way? Anthropologists understand that neither way is better and that each addresses a need within a particular culture.

Anthropology is the study of humanity guided by a distinctive narrative and set of commitments.

Marijuana use has generated similar controversies in other countries, including the United States, with some arguing that the drug provides relaxation and pain relief while others claim it interferes with cognitive abilities and motivation.

Anthropology teaches a set of skills for setting aside personal perspectives and keeping an open mind while learning about the diversity of human practices and ideas.

The team is exploring how smartphones take on different functions in different cultural contexts.

does not mean abandoning individual personal values, but rather suspending judgment temporarily while learning to understand the perspectives of others.

elements that may seem unfamiliar or uncomfortable

women have always played a role in hunting game

Anthropology aims to overcome bias by examining cultures as complex, integrated products of specific environmental and historical conditions

Haas found that this hunter from long ago was a young woman. This discovery has upset the notion that hunting was the exclusive activity of men throughout human evolutionary history.

Though they conduct research on vastly different topics, all three are anthropologists.

understand the full experience of humanity

She collects urine and feces to analyze hormone levels, intestinal parasites, and DNA. She wants to understand how primates compete as individuals and groups for access to various foods in their environment.

Anthropology, the study of humanity, is guided by a central narrative and set of research commitments.

Early deployments of the term Xicana include Ana Castillo’s critical text Massacre of the Dreamers: Essays on Xicanisma (1994) and La Red Xicana Indígena, an organization founded in 1997.

She accounts for the Arab and North African racial mixing that shaped Iberian culture and the subsequent racial mixture with Indigenous peoples of the Americas during the Spanish conquest.

She argues these multiple sites of sexism across time and space have led to the subordination of Indigenous womanhood and are a result of spiritual imbalance due to the omission of the “feminine principle.”

Contemporary Xicana feminist sonic, lexical, and political replacements of the Ch with an X are meant to point to Indigenous uprisings within and throughout Chicana, Chicano, and Chicanx identities. Today, the spoken and written grapheme X acts as a mobile signifier that points to identities-in-redefinition."60

Chicana feminists continued to intervene in Chicano nationalist constructions of Indigeneity by unsettling myths and binaries that were delineated during El Movimiento through Xicanisma, an embodied feminist philosophy and praxis.

To do this, she writes, would restore spiritual balance. This restorative act challenges U.S. white supremacy, Chicano heteropatriarchy, and the Catholic Church––all rely on stringent dichotomies that repress women’s spirituality and sexuality.

Cherríe Moraga explains her use of the X indicates “a reemerging política, especially among young people, grounded in Indigenous American belief systems and identities... [that] reflects the Indian identity that has been robbed from us through colonization

an innovative expansion of previous biologically based definitions of mestizaje.

Mestiza consciousness is a cognitive decolonization process of racialized, gendered, and sexed subjects wherein la mestiza becomes aware of the Borderlands and makes conscious decisions regarding the construction of her multiple and often contradictory identities.

A frequency polygon for 642 psychology test scores shown in Figure 2.2.82.2.8\PageIndex{8} was constructed from the frequency table shown in Table 2.2.22.2.2\PageIndex{2}.

Frequency polygons are also a good choice for displaying cumulative frequency distributions

The histogram makes it plain that most of the scores are in the middle of the distribution, with fewer scores in the extremes. You can also see that the distribution is not symmetric: the scores extend to the right farther than they do to the left. The distribution is therefore said to be skewed. (We'll have more to say about shapes of distributions in Chapter 3.)

Interval's Lower Limit Interval's Upper Limit Class Frequency

Notice that each stem value is split into five parts: 0-1, 2-3, 4-5, 67, and 8-9.

Observe that the figure contains a row headed by “0” and another headed by “-0.” The stem of 0 is for numbers between 0 and 9, whereas the stem of -0 is for numbers between 0 and -9.

Thus, the value 43.2 is rounded to 43 and represented with a stem of 4 and a leaf of 3. Similarly, 42.9 is rounded to 43. To represent negative numbers, we simply use negative stems.

First, the data are limited to whole numbers that can be represented with a one-digit stem and a one-digit leaf.

Figure 2.2.42.2.4\PageIndex{4}: Back-to-back stem and leaf display. The left side shows the 1998 TD data and the right side shows the 2000 TD data.

To make this clear, let us examine Figure 2.2.22.2.2\PageIndex{2} more closely. In the top row, the four leaves to the right of stem 3 are 2, 3, 3, and 7. Combined with the stem, these leaves represent the numbers 32, 33, 33, and 37, which are the numbers of TD passes for the first four teams in Figure 2.2.12.2.1\PageIndex{1}.

The numbers to the right of the bar are leaves, and they represent the 1’s digits. Every leaf in the graph therefore stands for the result of adding the leaf to 10 times its stem.

A stem of 3, for example, can be used to represent the 10’s digit in any of the numbers from 30 to 39.

Scatter plots are used to show the relationship between two variables.

This is why librarians and your instructors are constantly asking you to take advantage of your academic privilege by using the library databases.

The good news is that academics, librarians, and even the government are pushing for more open access to academic material.

Students, even those in high school, enjoy information privileges that aren't afforded to the general public

This is why librarians and your instructors are constantly asking you to take advantage of your academic privilege by using the library databases. My hope is that someday more academic information will be freely available. Until then - we should all be part of this fight.

The good news is that academics, librarians, and even the government are pushing for more open access to academic material

We are active users of technology - I am teaching and you are learning online. When we're submerged in this kind of environment, it's sometimes easy to forget that what's known as the digital divide still exists.

I am teaching and you are learning online. When we're submerged in this kind of environment

The good news is that academics, librarians, and even the government are pushing for more open access to academic material.

Students, even those in high school, enjoy information privileges that aren't afforded to the general public.

When we're submerged in this kind of environment, it's sometimes easy to forget that what's known as the digital divide still exists. Our access to technology gives us advantages in accessing information that many around the world do not have.

inally, we note that it is a serious mistake to use a line graph when the X-axis contains merely qualitative variables. A line graph is essentially a bar graph with the tops of the bars represented by points joined by lines (the rest of the bar is suppressed).

Figure 2.1.52.1.5\PageIndex{5}: A redrawing of Figure 2.1.22.1.2\PageIndex{2} with a lie factor greater than 8.

For example, 3-dimensional bar charts such as the one shown in Figure 2.1.42.1.4\PageIndex{4} are usually not as effective as their two-dimensional counterparts.

Figure 2.1.32.1.3\PageIndex{3}: A bar chart of the number of people playing different card games on Sunday and Wednesday.

Bar charts Bar charts can also be used to represent frequencies of different categories.

For example, if just 5 people had been interviewed by Apple Computers, and 3 were former Windows users, it would be misleading to display a pie chart with the Windows slice showing 60%.

Pie charts are effective for displaying the relative frequencies of a small number of categories. They are not recommended, however, when you have a large number of categories.

The pie chart in Figure 2.1.12.1.1\PageIndex{1} shows the results of the iMac study. In a pie chart, each category is represented by a slice of the pie. The area of the slice is proportional to the percentage of responses in the category. This is simply the relative frequency multiplied by 100. Although most iMac purchasers were Macintosh owners, Apple was encouraged by the 12% of purchasers who were former Windows users, and by the 17% of purchasers who were buying a computer for the first time.

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All of the graphical methods shown in this section are derived from frequency tables. Table 1 shows a frequency table for the results of the iMac study; it shows the frequencies of the various response categories. It also shows the relative frequencies, which are the proportion of responses in each category. For example, the relative frequency for “none” of 0.17 = 85/500.

The key point about the qualitative data that occupy us in the present section is that they do not come with a pre-established ordering (the way numbers are ordered).

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Both primitivism and orientalism were developed when Europeans were colonizing these parts of the world

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Other: __________________________

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The prefix "iso" implies that the connection ends with a (CH3)2CH- group.

discrete

Some study our closest animal relatives, the primates, in order to understand what biological and social traits humans share with primates and explore what makes humans unique in the animal world.

__________________dans

|𝑥−𝑐|<𝛿⟶|𝑦−𝐿|<𝜖

S-strain

Una persona que juega al tenis es __________.

Thus, according to Jung, the collective unconscious is a reservoir of psychic resources common to all humans (something along the lines of psychological instinct). These psychic resources, known as archetypes, are passed down through the generations of a culture, but Jung considered them to be inherited, not learned. As generation after generation experienced similar phenomena, the archetypal images were formed. Despite cultural differences, the human experience has been similar in many ways throughout history. As such, there are certain archetypes common to all people. According to Jung, the most empirically valid archetypes, and therefore the most powerful, are the shadow, the anima, and the animus (Jung, 1959c).

−

−Kion

Differential

University

city

As a result of this personality change, he was fired and could no longer hold a steady job

In April 2013, the BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative was launched. The focus of this initiative was to advance our understanding of the human brain. In the fiscal year 2020, 10.1 billion U.S. dollars has been allocated to neuroscience studies (Mikulic, 2021). Different institutions, agencies and foundations such as Food and Drug Administration, Defense Advanced Research Projects Agency, have joined in this effort.

Early philosophers, such as Aristotle (384-322 B.C.E.), believed that one's mind resided in the heart. He believed that since our blood started from the heart, the soul also originated there. Plato (428-347 B.C.E.) argued that the executor of reason was the heart and our animalistic desires and emotions were controlled by the liver (Gross, 1987). Many ancient cultures, including the Chinese, Indian, and Egyptian also shared the same belief (Carlson, 2014). When the Egyptians embalmed a person, the heart was saved and buried with the individual but the brain was discarded (Klein and Thorne, 2006). However, there were early Greeks, such as Hippocrates (460-377 B.C.E.) , who believed that it was the brain and not the heart where the locus of the mind resided. He wrote: "It ought to be generally known that the source of our pleasure, merriment, laughter, and amusement, as of our grief, pain, anxiety, and tears is none other than the brain. It is specially the organ which enables us to think, see, and hear......It is the brain too which is the seat of madness and delirium, of the fears and frights which assail us" (Gross, 1987, p. 843-844). During the 3rd Century B.C., in Alexandria, a science museum was established. Since human dissection was practiced in that city for centuries, the anatomical study of the human body flourished (Gross, 1987). Two neuroanatomists, Herophilos and Erasistratos, contributed to our knowledge of the human brain. Herophilos distinguished the cerebellum (at the very base of the back of the brain) and the cerebrum (the two cerebral hemispheres). He hypothesized that since the cerebellum was denser than the other parts of the brain, it must control the muscles (a guess of impressive accuracy). And he provided the first clear description of the cavities within the brain known as ventricles (Figure 1.2.1). Erasistratos continued the work of Herphilos and proposed that human intelligence was related to the number of convolutions (ridges) in the brain; the more convolutions an individual's brain had, the more intelligent that person would be.

It is important to examine the historical path of our understanding of the brain and its role in our behavior and mental processes. Examining the history of biopsychology allows us to understand its development over time, highlighting instances where researchers were wrong about the nature of brain-behavior relationships and revealing what we have yet to explain (Saucier and Elias, 2006). Studying the history of a scientific discipline gives us a roadmap of where we have traveled from and in what direction we need to go

Biopsychology as a scientific discipline emerged from a variety of scientific and philosophical traditions in the 18th and 19th centuries. Although the exact date of inception of biological psychology is unknown, there have been a number of milestones in its emergence.  William James in his book, The Principles of Psychology (1890), argued that the scientific study of psychology should be grounded in an understanding of biology (Walinga, 2014). Like many early psychologists, James had extensive training in physiology.

each one filled with a chemical solution that allowed the hearts to continue to beat.

brain areas become more active, more blood flows to that area

positron emission tomography (PET) scans

case where a young man had sustained damage to the left frontal lobe and as a result was unable to produce spoken speech. However, the patient was able to comprehend speech and had average intelligence. After his death, Broca performed an autopsy and determined that the patient had a lesion in the frontal lobe

ocrates (460-377 B.C.E.) , who believed that it was the brain and not the heart where the locus of the mind resided. He wrote: "It ought to be generally known that the source of our pleasure, merriment, laughter, and amusement, as of our grief, pain, anxiety, and tears is none other than the brain. It is specially the organ which enables us to think, see, and hear......It is the brain too which is the seat of madness and delirium, of the fears and fright

believed that one's mind resided in the heart

CT scans can be used to locate brain tumors, injury, or atrophy. However, the CT scan uses Xrays to provide an image of the brain which could pose risk to brain tissue.

Roman Empire, the Greek anatomist Galen (A.D. 130-200) dissected the brains of sheep, monkeys, dogs, pigs, among other non-human mammals (Carlson, 2014). He believed the brain to be the site of sensation and thought, and the controller of movement (Gross, 1987). He stated that spinal cord was an extension of the brain and chronicled the relationship between the spinal nerves and specific muscles each controlled. For the next advance in understanding spinal function, we must await Bell and Magendie in the 19th Century.

Hippocrates (460-377 B.C.E.) , who believed that it was the brain and not the heart where the locus of the mind resided. He wrote: "It ought to be generally known that the source of our pleasure, merriment, laughter, and amusement, as of our grief, pain, anxiety, and tears is none other than the brain. It is specially the organ which enables us to think, see, and hear......It is the brain too which is the seat of madness and delirium, of the fears and frights which assail us"

Two neuroanatomists, Herophilos and Erasistratos,

Plato (428-347 B.C.E.) argued that the executor of reason was the heart and our animalistic desires and emotions were controlled by the liver

(384-322 B.C.E.), believed that one's mind resided in the heart. He believed that since our blood started from the heart, the soul also originated there.

invention of methods such as the electroencephalogram (EEG) and computed tomography (CT or CAT) scans, scientists began to link the brain to specific behavior and cognition as biopsychology as a discipline began to emerge.

case studies such as Phineas Gage

1949, Donald Hebb wrote his influential book, The Organization of Behavior, where he introduced the first comprehensive theory on how the brain might create and control complex psychological functioning, such as thought, memories, emotions and perceptions.

An Outline of Psychobiology,  Knight Dunlap used the term "psychobiology" to explain the role of biology in behavior.

William James in his book, The Principles of Psychology (1890), argued that the scientific study of psychology should be grounded in an understanding of biology

Biopsychology as a scientific discipline emerged from a variety of scientific and philosophical traditions in the 18th and 19th centuries.

the belief that all events in the universe have prior causes and that these causes are external to the human will.  This implies that humans do not have free will.  Instead human behavior is caused by events external to us such as our upbringing, our social and cultural environment, by our brain structure and functioning, and by our genes and our evolution as a species.

Most important to biopsychology is the application of this principle to psychology and psychological processes.  If everything in the universe is physical, then applied to psychology, including biopsychology, this means that the mind, our mental processes and subjective mental experiences, must also be entirely physical processes in an entirely material brain.

This view of the universe is called materialism or physicalism--the view that everything that exists in the universe consists of matter, energy, and other physical forces and processes.

The frequently repeated claim that humans use only 10% of their brains is false. The exact origin of this myth is unknown, but misinterpretations of brain research are likely to blame. In experiments with animal brains during the 1800's through the early 1900's, Marie-Jean-Pierre Flourens and Karl Lashley destroyed and/or removed as much as 90% of the brain tissue of their animal subjects.  Nevertheless, these animals could still perform basic behavioral and physiological functions. Some who read these results made the incorrect assumption that this meant that animals were using only 10% of their brains.  Subsequently, this interpretation was generalized to humans (Elias and Saucer, 2006). Furthermore, prominent psychologists and researchers, such as Albert Einstein, Margaret Mead, and William James, were also quoted as saying that humans are using only a small portion of their brain (Elias and Saucer, 2006), fueling the 10% myth. Due to advances in biopsychology and other related fields, we now have a greater understanding of the complexity of the brain. We may not be using our brains as efficiently as possible at all times, but we are using the entirety of our brain as each part contributes to our daily functioning.  Studies of humans with brain damage have revealed that the effects of brain damage are correlated with where the damage is and how extensive it is. In other words, where damage occurs determines what functions are impacted and more damage has more of an effect. This reflects a key organizational principle of the brain: the localization of function.  This principle means that specific psychological and behavioral processes are localized to specific regions and networks of the brain.  For example, we now know that damage to an area of the brain known as the primary visual cortex, at the very back of your head in the occipital lobe, will result in blindness even though the rest of your visual system, including your eyes, is functioning normally. This syndrome is known as cortical blindness, to distinguish it from blindness that is caused by damage to the eyes.  We now know that damage to a small area less than the size of a quarter at the very base of your brain results in disruption of feeding and regulation of body weight.  Damage to another area of the brain located near your temples disrupts your ability to form new memories for facts and events, while leaving your ability to learn new motor tasks (such as skating or riding a bike) completely unaffected.  Damage to another brain area causes face blindness, or prosopagnosia, a disorder in which the afflicted individual can still see normally except that they cannot recognize familiar faces, even the faces of close family members or even their own face in a photograph.  In the pages that follow in this textbook, you will learn many amazing things about the brain, and the nervous system in general.  Get ready for many surprises as we explore the 3 pounds of brain tissue between our ears that make up the most complex piece of matter in the known universe. In this book, we examine some of what scientists now know about this astonishing organ, the brain, and how it functions to produce mind and behavior.

humans use only 10% of their brains is false.

Psychology is the scientific study of behavior and mental processes in animals and humans. Modern psychology attempts to explain behavior and the mind from a wide range of perspectives. One branch of this discipline is biopsychology which is specifically interested in the biological causes of behavior and mental processes.  Biopsychology is also referred to as biological psychology, behavioral neuroscience, physiological psychology, neuropsychology, and psychobiology. The focus of biopsychology is on the application of the principles of biology to the study of physiological, genetic, evolutionary, and developmental mechanisms of behavior in humans and other animals. It is a branch of psychology that concentrates on the role of biological factors, such as the central and peripheral nervous systems, neurotransmitters, hormones, genes, and evolution on behavior and mental processes. Biological psychologists are interested in measuring biological, physiological, or genetic variables in an attempt to relate them to psychological or behavioral variables. Because all behavior is controlled by the central nervous system (brain and spinal cord), biopsychologists seek to understand how the brain functions in order to understand behavior and mental activities. Key areas of focus within the field include sensation and perception; motivated behavior (such as hunger, thirst, and sex); control of movement; learning and memory; sleep and biological rhythms; and emotion. With advances in research methods, more complex topics such as language, reasoning, decision making, intelligence, and consciousness are now being studied intensely by biological psychologists.

Biopsychology is the study of biological mechanisms of behavior and mental processes.  It examines the role of the nervous system, particularly the brain, in explaining behavior and the mind. This section defines biopsychology, critically examines a common myth about the brain, and briefly surveys some of the primary areas of research interest in biopsychology.

help psychologists understand the link between brain and behavior.

critically examines a common myth about the brain

Free will vs. determinism is an issue that is far from being resolved and remains controversial even among scientists, including biological psychologists.

mental experiences, must also be entirely physical processes in an entirely material brain

cans of the head are often used to help psychologists understand the links between brain and behavior

second major assumption among most scientists is determinism

Because all behavior is controlled by the central nervous system (brain and spinal cord), biopsychologists seek to understand how the brain functions in order to understand behavior and mental activitie

s mind-body dualism or mind-brain dualism, which literally means that the mind and the functioning of the brain (assumed to be entirely physical) are two (dual) separate processes, completely independent of one another.  The origin of dualism is often attributed to the 17th century French philosopher and mathematician, Rene Descartes. If this view were true, then we would expect that brain damage would have no effect on the mind.  However, brain damage does affect the mind and the specific location of the damage produces more or less specific, fairly predictable, effects on the mind, modifying the mind and behavior in various ways.  Examples of this are coma due to head injury; the effects of Parkinson's disease on movement after the disease damages areas of the brain known as the basal ganglia; changes in personality and emotion due to injury to the front of the brain, specifically the frontal lobes; memory loss in Alzheimer's Disease; and so on.  Though you don't have to accept the assumption of physicalism when studying the brain if your religious beliefs are contrary to the idea, nevertheless it is important that you be aware of the assumption of physicalism/materialism that most biological psychologists accept, at least as a working hypothesis, if not a philosophical position, as they do their brain research.

Although this is the view among most biological psychologists, there are a few who believe, like many students do, that the brain, along with the rest of life, was created by a divine being and that therefore the mind has divine origins

The scientific answer is evolution.

That is, a mind, consciousness, can only emerge from matter, energy, and physical processes if they are organized in a very specific and complex form--that form that we know as a brain and its physical operations.

subjective

principle

Different brain-imaging techniques provide scientists with insight into different aspects of how the human brain functions.

Magnetic resonance imaging (MRI

PET scan (positron emission tomography), CT scan (computed tomography),

functional magnetic resonance imaging (fMRI) scans

neurochemical makeup,

This folding increases in mammal species with increasing complexity of the brain of the species and is thought to originate from the "cramming" of more cortical tissue into the skull over evolutionary time.

specific psychological and behavioral processes are localized to specific regions and networks of the brain.

incorrect assumption

key organizational principle of the brain: the localization of function

destroyed and/or removed as much as 90% of the brain tissue of their animal subjects

humans use only 10% of their brains is false.

branch of

measuring biological, physiological, or genetic variables in an attempt to relate them to psychological or behavioral variables.

attempts to explain behavior and the mind from a wide range of perspectives

study of biological mechanisms of behavior and mental processes.

language, reasoning, decision making, intelligence, and consciousness

sensation and perception; motivated behavior (such as hunger, thirst, and sex); control of movement; learning and memory; sleep and biological rhythms; and emotion

all behavior is controlled by the central nervous system (brain and spinal cord), biopsychologists seek to understand how the brain functions

concentrates on the role of biological factors, such as the central and peripheral nervous systems, neurotransmitters, hormones, genes, and evolution on behavior and mental processes.

application of the principles of biology to the study of physiological, genetic, evolutionary, and developmental mechanisms of behavior in humans and other animals

Psychology is the scientific study of behavior and mental processes in animals and humans.

role of the nervous system, particularly the brain, in explaining behavior and the mind.

biological psychology, behavioral neuroscience, physiological psychology, neuropsychology, and psychobiology

specifically interested in the biological causes of behavior and mental processes.

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Artificial intelligence

My professors encourage academic freedom

Table 1.4.11.4.1\PageIndex{1}: Base Units of the SI System Property Measured Name of Unit Symbol of Unit length meter m mass kilogram kg time second s temperature kelvin K electric current ampere A amount of substance mole mol luminous intensity candela cd

∝(19A.2)(19A.2)at=r∝ a_t=r \propto \label{19-1} A Rotating Rigid Body The characterization of the motion of a rotating rigid body has a lot in common with that of a particle traveling on a circle. In fact, every particle making up a rotating rigid body is undergoing circular motion. But different particles making up the rigid body move on circles of different radii and hence have speeds and accelerations that differ from each other. For instance, each time the object goes around once, every particle of the object goes all the way around its circle once, but a particle far from the axis of rotation goes all the way around circle that is bigger than the one that a particle that is close to the axis of rotation goes around. To do that, the particle far from the axis of rotation must be moving faster. But in one rotation of the object, the line from the center of the circle that any particle of the object is on, to the particle, turns through exactly one rotation. In fact, the angular motion variables that we have been using to characterize the motion of a line extending from the center of a circle to a particle that is moving on that circle can be used to characterize the motion of a spinning rigid body as a whole. There is only one spin rate for the whole object, the angular velocity ωω\omega, and if that spin rate is changing, there is only one rate of change of the spin rate, the angular acceleration ∝∝\propto. To specify the angular position of a rotating rigid body, we need to establish a reference line on the rigid body, extending away from a point on the axis of rotation in a direction perpendicular to the axis of rotation. This reference line rotates with the object. Its motion is the angular motion of the object. We also need a reference line segment that is fixed in space, extending from the same point on the axis, and away from the axis in a direction perpendicular to the axis. This one does not rotate with the object. Imagining the two lines to have at one time been collinear, the net angle through which the first line on the rigid body has turned relative to the fixed line is the angular position θθ\theta of the object. The Constant Angular Acceleration Equations While physically, there is a huge difference, mathematically, the rotational motion of a rigid body is identical to motion of a particle that only moves along a straight line. As in the case of linear motion, we have to define a positive direction. We are free to define the positive direction whichever way we want for a given problem, but we have to stick with that definition throughout the problem. Here, we establish a viewpoint some distance away from the rotating rigid body,but on the axis of rotation, and state that, from that viewpoint, counterclockwise is the positive sense of rotation, or alternatively, that clockwise is the positive sense of rotation. Whichever way we pick as positive, will be the positive sense of rotation for angular displacement (change in angular position), angular velocity, angular acceleration, and angular position relative to the reference line that is fixed in space. Next, we establish a zero for the time variable; we imagine a stopwatch to have been started at some instant that we define to be time zero. We call values of angular position and angular velocity, at that instant, the initial values of those quantities. Given these criteria, we have the following table of corresponding quantities. Note that a rotational motion quantity is in no way equal to its linear motion counterpart, it simply plays a role in rotational motion that is mathematically similar to the role played by its counterpart in linear motion. Linear Motion Quantity Corresponding Angular Motion Quantity xxx θθ\theta vvv ωω\omega aaa ∝∝\propto The one variable that the two different kinds of motion do have in common is the stopwatch reading ttt. Recall that, by definition, ω=dθdtω=dθdt \omega=\frac{d\theta}{dt} \nonumber and∝=dωdtand∝=dωdt\mbox{and} \quad \propto= \frac{d\omega}{dt} \nonumber While it is certainly possible for ∝∝\propto to be a variable, many cases arise in which ∝∝\propto is a constant. Such a case is a special case. The following set of constant angular acceleration equations apply in the special case of constant angular acceleration: (The derivation of these equations is mathematically equivalent to the derivation of the constant linear acceleration equations. Rather than derive them again, we simply present the results.) θ=θ0+ω0t+12∝t2(19A.3)(19A.3)θ=θ0+ω0t+12∝t2 \theta=\theta_0+\omega_0t+\frac{1}{2} \propto t^2 \label{19-2} θ=θ0+ω0+ω2t(19A.4)(19A.4)θ=θ0+ω0+ω2t \theta=\theta_0+\frac{\omega_0+\omega}{2} t \label{19-3} ω=ω0+∝t(19A.5)(19A.5)ω=ω0+∝t \omega=\omega_0+\propto t \label{19-4} ω2=ω20+2∝Δθ(19A.6)(19A.6)ω2=ω02+2∝Δθ \omega^2=\omega_0^2 +2\propto \Delta\theta \label{19-5} The rate at which a sprinkler head spins about a vertical axis increases steadily for the first 2.00 seconds of its operation such that, starting from rest, the sprinkler completes 15.0 revolutions clockwise (as viewed from above) during that first 2.00 seconds of operation. A nozzle, on the sprinkler head, at a distance of 11.0 cm from the axis of rotation of the sprinkler head, is initially due west of the axis of rotation. Find the direction and magnitude of the acceleration of the nozzle at the instant the sprinkler head completes its second (good to three significant figures) rotation. Solution We’re told that the sprinkler head spin rate increases steadily, meaning that we are dealing with a constant angular acceleration problem, so, we can use the constant angular acceleration equations. The fact that there is a non-zero angular acceleration means that the nozzle will have some tangential acceleration at→at→\vec{a_t}. Also, the sprinkler head is spinning at the instant in question so the nozzle will have some centripetal acceleration ac→ac→\vec{a_c}. We’ll have to find both at→at→\vec{a_t} and ac→ac→\vec{a_c} and add them like vectors to get the total acceleration of the nozzle. Let’s get started by finding the angular acceleration ∝∝\propto. We start with the first constant angular acceleration equation (equation 19A.319A.3\ref{19-2}): θ=0+0⋅t+12∝t2θ=0+0⋅t+12∝t2 \theta= 0+ 0\cdot t+\frac{1}{2} \propto t^2 \nonumber The initial angular velocity ω0ω0\omega_0 is given as zero. We have defined the initial angular position to be zero. This means that, at time t=2.00st=2.00st = 2.00 s, the angular position θθ\theta is 15.0rev=15.0 rev2π radrev=94.25rad15.0rev=15.0 rev2π radrev=94.25rad15.0 \, \mbox{rev}=15.0\space \mbox{rev}\frac{2\pi \space\mbox{rad}}{\mbox{rev}}=94.25 \mbox{rad}. Solving equation 19A.319A.3\ref{19-2} above for ∝∝\propto yields: ∝=2θt2∝=2θt2 \propto=\frac{2\theta}{t^2} \nonumber ∝=2(94.25rad)(2.00s)2∝=2(94.25rad)(2.00s)2 \propto=\frac{2(94.25 \mbox{rad})}{(2.00s)^2} \nonumber ∝=47.12rads2∝=47.12rads2 \propto=47.12 \frac{\mbox{rad}}{s^2} \nonumber Substituting this result into equation 19A.219A.2\ref{19-1}: at=r∝at=r∝a_t= r \propto \nonumber gives us at=(.110m)47.12rad/s2at=(.110m)47.12rad/s2 a_t=(.110m)47.12\mbox{rad}/s^2 \nonumber which evaluates to at=5.18ms2at=5.18ms2a_t=5.18 \frac{m}{s^2} \nonumber Now we need to find the angular velocity of the sprinkler head at the instant it completes 2.00 revolutions. The angular acceleration ∝∝\propto that we found is constant for the first fifteen revolutions, so the value we found is certainly good for the first two turns. We can use it in the fourth constant angular acceleration equation (equation 19A.619A.6\ref{19-5}): ω2=0+2∝Δθω2=0+2∝Δθ \omega^2= 0+2\propto \Delta\theta \nonumber where Δθ=2 rev=2.00 rev2π radrev=4.00π radΔθ=2 rev=2.00 rev2π radrev=4.00π rad\Delta\theta=2\space \mbox{rev}=2.00\space\mbox{rev}\frac{2\pi\space\mbox{rad}}{\mbox{rev}}=4.00\pi \space\mbox{rad} ω=2∝Δθ−−−−−−√ω=2∝Δθ\omega=\sqrt{2\propto\Delta\theta} \nonumber ω=2(94.25rad/s2)4.00πrad−−−−−−−−−−−−−−−−−−−√ω=2(94.25rad/s2)4.00πrad\omega=\sqrt{2(94.25 \mbox{rad}/s^2)4.00\pi \mbox{rad}} \nonumber \omega=48.67 \mbox{rad}/s\label{19-6}\omega=48.67 \mbox{rad}/s\label{19-6}\omega=48.67 \mbox{rad}/s\label{19-6} (at that instant when the sprinkler head completes its 2nd turn) Now that we have the angular velocity, to get the centripetal acceleration we can use equation ??????\ref{18-6}: ac=rω2ac=rω2 a_c=r\omega^2 \nonumber ac=.110m(48.67rad/s)2ac=.110m(48.67rad/s)2 a_c=.110m(48.67 \mbox{rad}/s)^2 \nonumber ac=260.6ms2ac=260.6ms2a_c=260.6 \frac{m}{s^2} \nonumber Given that the nozzle is initially at a point due west of the axis of rotation, at the end of 2.00 revolutions it will again be at that same point. Now we just have to add the tangential acceleration and the centripetal acceleration vectorially to get the total acceleration. This is one of the easier kinds of vector addition problems since the vectors to be added are at right angles to each other. From Pythagorean’s theorem we have a=a2c+a2t−−−−−−√a=ac2+at2 a=\sqrt{a_c^2+a_t^2} \nonumber a=(260.6m/s2)2+(5.18m/s2)2−−−−−−−−−−−−−−−−−−−−−−√a=(260.6m/s2)2+(5.18m/s2)2 a=\sqrt{(260.6m/s^2)^2+(5.18m/s^2)^2} \nonumber a=261m/s2a=261m/s2 a=261m/s^2 \nonumber From the definition of the tangent of an angle as the opposite over the adjacent: tanθ=atactanθ=atac tan\theta=\frac{a_t}{a_c} \nonumber θ=tan−15.18m/s2260.6m/s2θ=tan−15.18m/s2260.6m/s2 \theta=tan^{-1} \frac{5.18 m/s^2}{260.6m/s^2} \nonumber θ=1.14∘θ=1.14∘\theta=1.14^{\circ} \nonumber Thus, a=261m/s2at 1.14∘ North of Easta=261m/s2at 1.14∘ North of Easta=261m/s^2 \quad \mbox{at \(1.14^{\circ}\) North of East} \nonumber When the Angular Acceleration is not Constant The angular position of a rotating body undergoing constant angular acceleration is given, as a function of time, by our first constant angular acceleration equation, equation 19A.319A.3\ref{19-2}: θ=θ0+ω0t+12∝t2θ=θ0+ω0t+12∝t2\theta=\theta_0+\omega_0t+\frac{1}{2}\propto t^2 \nonumber If we take the 2nd derivative of this with respect to time, we get the constant ∝∝\propto. (Recall that the first derivative yields the angular velocity ωω\omega and that ∝=dωdt∝=dωdt\propto=\frac{d\omega}{dt}. ) The expression on the right side of θ=θ0+ω0t+12∝t2θ=θ0+ω0t+12∝t2\theta=\theta_0+\omega_0t+\frac{1}{2}\propto t^2 contains three terms: a constant, a term with ttt to the first power, and a term with ttt to the 2nd power. If you are given θθ\theta in terms of ttt, and it cannot be rearranged so that it appears as one of these terms or as a sum of two or all three such terms; then; ∝∝\propto is not a constant and you cannot use the constant angular acceleration equations. Indeed, if you are being asked to find the angular velocity at a particular instant in time, then you’ll want to take the derivative dθdtdθdt\frac{d\theta}{dt} and evaluate the result at the given stopwatch reading. Alternatively, if you are being asked to find the angular acceleration at a particular instant in time, then you’ll want to take the second derivative d2θdt2d2θdt2\frac{d^2\theta}{dt^2} and evaluate the result at the given stopwatch reading. Corresponding arguments can be made for the case of ωω\omega. If you are given ωω\omega as a function of ttt and the expression cannot be made to “look like” the constant angular acceleration equation ω=ω0+∝

Stereotypes are sets of beliefs that we develop about groups, which we then apply to individuals from that group.

Prejudice is negative feelings or attitudes toward people based on their identity or identities. Prejudice can have individual or widespread negative effects.

Interpretation is the third part of the perception process, in which we assign meaning to our experiences using mental structures known as schemata.

Organizing is the second part of the perception process, in which we sort and categorize information that we perceive based on innate and learned cognitive patterns.

Selecting is the first part of the perception process, in which we focus our attention on certain incoming sensory information.

Ancient Greek philosophers and scholars such as Aristotle theorized about the art of rhetoric, which refers to speaking well and persuasively. Today, we hear the word rhetoric used in negative ways. A politician, for example, may write off his or her opponent’s statements as “just rhetoric.” This leads us to believe that rhetoric refers to misleading, false, or unethical communication, which is not at all in keeping with the usage of the word by ancient or contemporary communication experts. While rhetoric does refer primarily to persuasive communication messages, much of the writing and teaching about rhetoric conveys the importance of being an ethical rhetor, or communicator. So when a communicator, such as a politician, speaks in misleading, vague, or dishonest ways, he or she isn’t using rhetoric; he or she is being an unethical speaker.

Max Planck explain the spectral distribution of blackbody radiation as result from oscillations of electrons. Similarly, oscillations of electrons in an antenna produce radio waves. Max Planck concentrated on modeling the oscillating charges that must exist in the oven walls, radiating heat inwards and—in thermodynamic equilibrium—themselves being driven by the radiation field. He found he could account for the observed curve if he required these oscillators not to radiate energy continuously, as the classical theory would demand, but they could only lose or gain energy in chunks, called quanta, of size hνhνh\nu, for an oscillator of frequency νν\nu

joke

The good news is that academics, librarians, and even the government are pushing for more open access to academic material.

Our access to technology gives us advantages in accessing information that many around the world do not have. This information graphic from the International Monetary Fund illustrates that:

Any language system has to have rules to make it learnable and usable. Grammar refers to the rules that govern how words are used to make phrases and sentences. Someone would likely know what you mean by the question “Where’s the remote control?” But “The control remote where’s?” is likely to be unintelligible or at least confusing (Crystal, 2005, p. 180). Knowing the rules of grammar is important in order to be able to write and speak to be understood, but knowing these rules isn’t enough to make you an effective communicator.

The triangle of meaning is a model of communication that indicates the relationship among a thought, symbol, and referent and highlights the indirect relationship between the symbol and referent (Richards & Ogden, 1923). As you can see in Figure 1, the thought is the concept or idea a person references. The symbol is the word that represents the thought, and the referent is the object or idea to which the symbol refers. This model is useful for us as communicators because when we are aware of the indirect relationship between symbols and referents, we are aware of how common misunderstandings occur.

For example, the word calculate comes from the Latin word calculus, which means “pebble.” But what does a pebble have to do with calculations? Pebbles were used, very long ago, to calculate things before we developed verbal or written numbering systems

Our language system is primarily made up of symbols. A symbol is something that stands in for or represents something else. Symbols can be communicated verbally (speaking the word hello), in writing (putting the letters H-E-L-L-O together), or nonverbally (waving your hand back and forth). In any case, the symbols we use stand in for something else, like a physical object or an idea; they do not actually correspond to the thing being referenced in any direct way. Unlike hieroglyphics in ancient Egypt, which often did have a literal relationship between the written symbol and the object being referenced, the symbols used in modern languages look nothing like the object or idea to which they refer.

We arrive at meaning through the interaction between our nervous and sensory systems and some stimulus outside of them. It is here, between what the communication models we discussed earlier labeled as encoding and decoding, that meaning is generated as sensory information is interpreted.

there have been more than 126 published definitions of communication (Dance & Larson, 1976).

slowly reverting later

Today, it is well understood that the prefrontal cortex of the brain controls the organization of behavior, including emotions and inhibitions.