Further Experiments
By filling the tube with other gases besides air, and partially evacuating it with a vacuum pump, Kundt was also able to calculate the speed of sound in different gases at different pressures. To create his vibrations, Kundt stopped the other end of the tube with a loose fitting stopper attached to the end of a metal rod projecting into the tube, clamped at its center. When it was rubbed lengthwise with a piece of leather coated with rosin, the rod vibrated longitudinally at its fundamental frequency, giving out a high note. Once the speed of sound in air was known, this allowed Kundt to calculate the speed of sound in the metal of the resonator rod. The length of the rod L was equal to a half wavelength of the sound in metal, and the distance between the piles of powder d was equal to a half wavelength of the sound in air. So the ratio of the two was equal to the ratio of the speed of sound in the two materials:
Read more about this topic: Kundt's Tube
Famous quotes containing the word experiments:
“The true thrift is always to spend on the higher plane; to invest and invest, with keener avarice, that he may spend in spiritual creation, and not in augmenting animal existence. Nor is the man enriched, in repeating the old experiments of animal sensation; nor unless through new powers and ascending pleasures he knows himself by the actual experience of higher good to be already on the way to the highest.”
—Ralph Waldo Emerson (1803–1882)
“My experiments did not turn out quite like yours, Henry. But science, like love, has her little surprises.”
—William Hurlbut (1883–?)