The Physics Of Sound Essays - Acoustics, Waves, Sound,

The Physics Of Sound Sound surrounds us at all times. The ring of an alarm clock or the whistle of birds may wake us up in the morning. Through out the day, we hear a variety of sounds; for instance, the banging of pots and pans, the roar of traffic, and the voices of people. When we fall asleep at night, we might listen to the sounds of frogs croaking or the wind whistling. All sounds have one thing in common. This being that the vibrations of an object makes every sound. When an object vibrates, it causes the air around it to vibrate. The vibrations in the air travel out from all directions of the object. They then reach our ears, and the brain reads them as sounds. Many sounds we hear travel through the air; however, they can also travel through solid objects like the earth. Our voice is made in the larynx, which is a part of the throat. Two small pieces of tissue are spread across the larynx. These pieces, called vocal chords, make the opening smaller. Air from he lungs quickly passes trough the tightened chords, causing them to vibrate. The vibrations make the sound of the voice. The tighter the chords are, the faster the vibrations and the higher the resulting sound. If a rock is thrown onto a still pond, several waves travel out from the place where the rock hit the surface. Likewise, sound moves in waves through the air or some other medium. The understanding that sound travels in the form of waves may have originated with the artist Leonardo Da Vinci in 1500. Generally, waves can be spread transversely or longitudinally. In both cases, only the energy of wave motion is spread through medium. No portion of the medium actually moves very far. As the waves caused by the moving object travel outward, they are carried by a medium. This movement causes compression. As the movements move backward it is called rarefractions. Sound requires a medium to travel; therefore, it cannot travel in space, which is a vacuum with no medium. The number of compressions and rarefractions per second is called frequency, The more rapidly and object vibrates, the higher the frequency. Frequency is measured in hertz. As the frequency of a sound wave increases, the wavelength decreases. Wavelength is the distance between one point on a wave to the corresponding point on the next wave. Most people hear sounds with frequencies that fall between 20 and 20,000 hertz. Many animals can hear sounds about 20,000 hertz. A person's voice can have a range of about 85 to 1,100 hertz. When sound waves leave one medium and enter another in which the speed of sound differs, the direction of the waves is altered. This change in direction results from a change in the speed of waves called refraction. Sound waves can also be refracted if the speed of the sound changes according to their position in a medium. The waves bend toward the region of slower speed. Sound travels farther when the air is cooler. During the day, the ground is warmer than the air above. Sound waves are bent away from the ground into the cooler air above, where their speed is slower allowing the sound to be heard over longer distances. The spreading out of waves as they pass by the edge of an obstacle or through and opening is called diffraction. It occurs whenever a sound wave encounters an obstacle or opening. Diffraction enables sound to be heard around a corner, even though no straight path exists from the source of the sound to the ear. If sound travels at about the same speed in both materials with the same density, little sound will be reflected. Instead, most of the sound will be transmitted into the new medium. If the speed differs greatly in the two mediums and their densities are greatly different, most of the sound will be reflected. The intensity of a sound is related to the amount of energy in the sound waves. Intensity depends on the amplitude of the vibrations making the waves. Amplitude is the distance that the object producing the sound travels as it vibrates.

Literature that Changed America Essays

Literature that Changed America Essays Literature that Changed America Essay Literature that Changed America Essay Every now and then a piece of literature will come around and change the world. Maybe it will start a revolution or shine light on an important issue, no matter what there will be a transformation in culture. Only looking back into retrospect can one recognize how much of an impact has been actually left by pieces of significant literature. Common Sense by Thomas Paine, Uncle Tom’s Cabin by Harriet Beecher Stowe and, The Jungle by Upton Sinclair are among just a few pieces that have radically changed and shaped the American Society. By January 1776, the colonies were in open conflict with Britain. They werent fighting in self-defense or to protect their property, but for independence. It took a hard reversal to move Americans from proclaimed reliability to announced rebellion, and it came from asubstantial part in Thomas Paines Common Sense. Thomas Paine was born in London, England into a quaker family. He was not well educated but was able to master reading, writing, and arithmetic. His early life was filled with many hardships including not being able to keep a job and the unfortunate death of his wife during childbirth. At a time when nothing in his life was going in the right direction, he met Benjamin Franklin. Franklin soon advised Paine to move to America and convinced him to become a writer. In 1774, Paine emigrated to Philadelphia, and after only one year he became co-editor of the Pennsylvania Magazine. After the Battle of Lexington in 1975, â€Å"Paine argued that America should not simply revolt ag ainst taxation, but demand independence from Great Britain entirely† (â€Å"Thomas Paine Biography† 2). And on January 10, 1776, he put this idea to work and published a 50 page pamphlet titled Common Sense. In this pamphlet, he explains why the people must stand up against King George III and the British Parliament. Due to how unfair they treated the colonies, Paine thought it was time to revolt. After studying the tension be

Descriptive Writting about the Beach in summertime Essay

Descriptive Writting about the Beach in summertime - Essay Example We smiled a grateful smile and raced towards its beginning but the waave had no beginning and no ending we just jumped in with a joy that could not be out into words but could be seen written on our faces as we marched onto the reason for our supreme ectasy we were proud to be finally at our destination- heaven a place where we belonged. We could not wait to make a dash for the welcoming waters. Our intense focus on the dazzling spectacle before us was interrupted when someone shouted, â€Å"Surf’s up, its summertime!† Everyone melted into spontaneous laughter. We could not contain our bliss and so it spilled over into utter desperation to taste the freedom and the energy that was summoning us to enter. This highly charged atmosphere was filled with the joie de vivre that exudes from a bridegroom as he is finally allowed to privately touch his virgin bride. Captivating silence was interjected with a sudden, loud splash and a bang. That was the announcement of the breakers as they crashed against the beckoning shore. The sea was like a roaring lion waiting to engulf us in its powerful jaw whilst the sheer brilliance of the sun painted the waters with shiny, shimmery, golden flecks. We could wait no longer and so triumphantly began our journey to reach the epitome of ecstasy. We were ready to fly. As the waves deafeningly appeared to draw closer and closer, beckoning us to its enthralling embrace, we succumbed to its bewitching effect and dashed off to grasp a drop of majestic splendor. We smiled a lovesick smile and raced towards its beginning but the breakers had no beginning and no ending. We were engulfed into its enormous hug and as a baby to its mother’s breast we breathed a breath of pure joy that could not be put into words but could be seen written on our faces as we longingly embraced the reason for our supreme ecstasy. We were