Steel is a rigid material with a high elasticity. A material such as steel will experience a very small deformation of shape (and dimension) when a stress is applied to it. Elastic properties are those properties related to the tendency of a material to maintain its shape and not deform whenever a force or stress is applied to it. Typically there are two essential types of properties that affect wave speed - inertial properties and elastic properties. The speed of any wave depends upon the properties of the medium through which the wave is traveling. Faster waves cover more distance in the same period of time. A slower wave would cover less distance - perhaps 660 meters - in the same time period of 2 seconds and thus have a speed of 330 m/s. If a sound wave were observed to travel a distance of 700 meters in 2 seconds, then the speed of the wave would be 350 m/s. The faster a sound wave travels, the more distance it will cover in the same period of time. In equation form, this is speed = distance/time Since the speed of a wave is defined as the distance that a point on a wave (such as a compression or a rarefaction) travels per unit of time, it is often expressed in units of meters/second (abbreviated m/s). Always be cautious to distinguish between the two often-confused quantities of speed ( how fast.) and frequency ( how often.). While frequency refers to the number of vibrations that an individual particle makes per unit of time, speed refers to the distance that the disturbance travels per unit of time. Like any wave, the speed of a sound wave refers to how fast the disturbance is passed from particle to particle. As one particle becomes disturbed, it exerts a force on the next adjacent particle, thus disturbing that particle from rest and transporting the energy through the medium. Because Regnault knew how far the gun was from the cylinder and how fast the cylinder turned, he calculated that sound travels through air at 750 miles per hour, quite close to the speed physicists accept today.A sound wave is a pressure disturbance that travels through a medium by means of particle-to-particle interaction. When the sound reached the diaphragm by the cylinder, the pen jumped back to its original position. When the gun fired, the first circuit broke, making the pen jump to a new position on the rotating cylinder. Next, he wired the pen to two electrical circuits, placing one in front of the gun some distance away, and the second near the cylinder, threaded through a diaphragm sensitive to sound. Regnault covered a rotating cylinder with paper, and positioned a pen to draw a line as it turned. In 1864, another French scientist, Henri Regnault, devised a way to measure the speed of sound automatically, again by using a gun, but without relying on human reaction time. The problem was that Gassendi relied on his own reaction time, making his measurement higher than it should have been. Knowing the exact distance the gun was from him, he calculated that sound traveled through air at over 1,000 miles per hour. Gassendi tried to measure the speed of sound by clocking the time that elapsed between the flash and the gunshot. When a gun fired far away, he could see the flash of gunshot long before he heard the report. In the 17th century, the French scientist Pierre Gassendi knew that light traveled faster than sound.
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