![]() ![]() Two approaches were employed to determine the velocity of sound in solids. ![]() Colladon came up with a speed of 1,435 metres per second at 8° C the presently accepted value interpolated at that temperature is about 1,439 metres per second. Strangely enough, his primary interest was not in measuring the speed of sound in water but in calculating water’s compressibility-a theoretical relationship between the speed of sound in a material and the material’s compressibility having been established previously. The speed of sound in water was first measured by Daniel Colladon, a Swiss physicist, in 1826. A more recent value for the speed of sound, 331.45 metres per second (1,087.4 feet per second), was obtained in 1942 it was amended in 1986 to 331.29 metres per second at 0° C (1,086.9 feet per second at 32° F). The earliest precise experimental value for the speed of sound, obtained at the Academy of Sciences in Paris in 1738, was 332 metres per second-incredibly close to the presently accepted value, considering the rudimentary nature of the measuring tools of the day. Bianconi demonstrated in 1740 that the speed of sound in air increases with temperature. In the 1650s, Italian physicists Giovanni Alfonso Borelli and Vincenzo Viviani obtained the much better value of 350 metres per second using the same technique. Although the value he obtained was too high-about 478.4 metres per second (1,569.6 feet per second)-he correctly concluded that the speed of sound is independent of frequency. Assuming correctly that the speed of light is effectively infinite compared with the speed of sound, Gassendi measured the time difference between spotting the flash of a gun and hearing its report over a long distance on a still day. In the 17th century, the French scientist and philosopher Pierre Gassendi made the earliest known attempt at measuring the speed of sound in air. Once it was recognized that sound is in fact a wave, measurement of the speed of sound became a serious goal.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |