Salvat,+J.

__ Questions: __ In a Paragraph or more tell the class your Interests, favorite subjects, favorite topics in science, least favorite topics in science, and what you Would Like to Learn This Year.

Hello my name is joshua and my interests are playing basketball and baseball. My favorite subjects are Math and Science. My favorite topics in Science are The Solar System and Machines. My least favorite topic is The Water Cycle because it is not interesting. The thing that i would like to learn this year is Chemistry so i could see how different thing react when you mix them together

__Research Paper__

The **wavelength** is the spatial period of the wave the distance over which the wave's shape repeats. It is usually noticed by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is the result of both traveling waves and standing waves, as well as other spatial wave patterns. The idea can also be used to periodic waves of not sinusoidal shape__. __The term //wavelength// is also sometimes used for modulated waves, and to the sinusoidal envelopes of modulated waves or waves made by interference of several sinusoids. The SI unit of wavelength is by meters.

Assuming a sinusoidal wave moving at a created wave speed, wavelength is inversely proportional to frequency: waves with higher frequencies have smaller wavelengths, and lower frequencies have more long wavelengths.

Examples of wave-like phenomena are sound waves, light, and water waves. A sound wave is a periodic variation in air pressure, while in light and other electromagnetic radiation the strength of the electric and the magnetic field depend. Water waves are periodic variations in the height of a body of water. In a crystal pattern vibration, atomic positions depend periodically in both pattern position and time.

Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how long or far any given particle moves. For example, in waves over deep water a particle in the water moves in a circle of the same diameter as the wave height.

Pitch is a sensation you hear in which a listener assigns musical tones to relative positions on a musical scale based on mostly the frequency of vibration. Pitch is very closely related to frequency, but both are not the same. Frequency is an objective, scientific concept, whereas pitch is subjective. Sound waves themselves don’t have pitch, and their vibrations can be measured to get a frequency. You have to have a human brain to map the internal quality of pitch.

Pitches are usually quantified as frequencies in cycles per second, or hertz, by comparing sounds with pure tones, which have periodic, sinusoidal waveforms. Complex and a periodic sound waves can often be given a pitch by this method.In most cases, the pitch of complex sounds such as speech and musical notes belong very nearly to the repetition rate of periodic or nearly-periodic sounds, or to the common of the time interval between repeating similar events in the sound waveform.

The pitch of complex tones can be vague, meaning that two or more different pitches can be apparent, pending upon the person. When the actual fundamental frequency can be exactly determined through physical measurement, it may be different from the supposed pitch because of overtones, also known as upper partials, harmonic or otherwise. The human auditory perception system also may have trouble distinguishing frequency differences between notes under certain circumstances.

A complex tone composed of two sine waves of 1000 and 1200 Hz may sometimes be heard as up to four pitches: two spectral pitches at 1000 and 1200 Hz, derived from the physical frequencies of the pure tones, and two combination tones at 200 Hz and 2200 Hz, derived from the repetition rate of the waveform. They also have a spectrum that is (approximately) a stack of harmonics and the apparent pitch is close to the harmonic spacing. The lowest harmonic in the stack is called the fundamental frequency, and its frequency is strongly linked with the pitch, though a strong pitch may be apparent even when the fundamental is gone.

Some theories of pitch observation hold that pitch has natural octave ambiguities, and therefore is best decomposed into a pitch chroma, a periodic value around the octave, like the names of the notes in western music, and a pitch height, which may be confusing, indicating which octave the pitch might be inside.

Pitch depends to less of a degree on the sound pressure level (loudness, volume) of the tone, most of all at frequencies lower than 1,000 Hz and higher than 2,000 Hz. The pitch of lower tones gets lower as sound pressure gets higher. For instance, a tone of 200 Hz that is very loud will seem to be one semitone lower in pitch than if it is just hard to hear. Higher than 2,000 Hz, the pitch gets higher as the sound gets louder.

Frequency is how many times of occurrences of a repeating event per unit time. It is also referred to as temporal frequency. The period is how long one cycle is in a repeating event, so the period is the equal of the frequency. For example, if a newborn baby's heart beats at a frequency of 120 times per minute, its period would be half of a second.

Sound is vibrations composed of frequencies eligible to be heard by ears. Frequency is the property of sound that most determines pitch.

Mechanical vibrations seeming as travel of sound through all forms of matter: gases, liquids, solids, and plasmas. The sound is supported by a mass called the medium. Sound can’t travel through a vacuum.The frequency range that can be heard for humans is limited to frequencies between about 20 Hz and 20,000 Hz (20 kHz). The older you are the less you can hear higher frequencies. It becomes more difficult to hear higher frequencies with the older you become. Other species have different hearing ranges. For an example, some dog breeds can perceive vibrations up to 60,000 Hz.

In SI units, the unit for frequency is hertz (Hz), it was named after Heinrich Hertz a German physicist, 1 Hz means that an event repeats one time per second. A past name for this unit of was cycles per second. Sound is a mechanical wave that is a fluctuation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be listened to, or organs of hearing having the sensation of being stimulated by such vibrations. Acoustics is the interdisciplinary science that has to deal with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician but someone who is working in the field of acoustics technology can be called an acoustical or an audio engineer. The application of acoustics is seen in almost all aspects of normal society with the most obvious being the audio and the noise control industries.

Musical acoustics or music acoustics is the branch of acoustics concerned with researching and the describing of musical physics. Examples of areas of study are the function of musical instruments, the human voice (the physics of speech and singing), computer analysis of melody, and in the clinical use of music in music therapy. Differences in air pressure hitting against the ear drum, and the subsequent physical and neurological processing and interpretation, give rise to the subjective experience called sound. Most sound that people remember as musical is dominated by periodic or regular vibrations instead of ones that are not periodic; that is, musical sounds typically have a definite pitch). The transmission of these differences through air is via a wave of sound. In a very simple case, the sound of a sine wave, which is considered to be the most basic model of a sound waveform, causes the air pressure to increase and decrease in a regular fashion, and is heard as a very pure tone. Pure tones can be produced by tuning forks or whistling. The rate at which the air pressure oscillates is the frequency of the tone, which is measured in oscillations per second, called hertz. Frequency is the primary determinant of the supposed pitch. Frequency of musical instruments can change with altitude due to changes in air pressure.

Whenever two different pitches are played at the same exact time, their sound waves interact with each other – the highs and lows in the air pressure reinforce each other to create a different wave of sound. As a result, any given sound wave which is more complicated than a sine wave can be modeled by lots of different sine waves of the correct frequencies and amplitudes (a frequency spectrum). The hearing device of the human (composed of the ears and brain) can usually separate these tones and hear them distinctly. When two or more tones are played at once, a variation of air pressure at the ear "contains" the pitches of each, and the ear and/or brain isolate and decode them into particular tones. When the original sound sources are perfectly periodic, the note consists of several related sine waves (which mathematically add to each other) called the essential and the harmonics, partials, or overtones. The sounds have harmonic frequency spectra. The lowest frequency present is the essential, and is the frequency at which the entire wave vibrates. The overtones vibrate faster than the fundamental, but must vibrate at numeral multiples of the fundamental frequency in order for the total wave to be exactly the same each cycle. Real instruments are close to periodic, but the frequencies of the overtones are not perfect, so the shape of the wave changes slightly over time.

By: Joshua Salvat Period 5