phy12 e302
YAMBAO, Monn Juleuse F. mjfyambao@gmail.com E304: Kundt's Tube: Velocity of Sound in Solid
METHODOLOGY
Two experiments were done last time due to some circumstances that made the class to lack time and to be late compared to the official class syllabus. The students were able to accomplished the job by equally dividing the time into two. The first experiment was about Kundt’s tube. In this experiment, longitudinal sound waves will be produced in a metal rod and an air column. Using the properties of wave motion , the frequency of the sound and the speed of sound in the rod can be determined.
For this experiment setup, following materials are needed such as a Kundt's tube apparatus, a meter stick, a piece of cloth, a thermometer, rosin, and lycopodium powder.
This experiment was done fast because of the fact that some of the procedures like placing a thin layer of lycopodium powder at least two millimetres wide as uniformly as possible inside the tube along its entire length was done already for us by the laboratory assistants. Then, a stopper was inserted in the end of the tube. Then, with the rod securely clamped at its center, the glass tube was positioned so that the disk on the end of the rod is a few centimeters within the tube and centered with respect to the sides. Before proceeding, the rod was confirmed to be at the right position by measuring the rod and make sure that it was clamped at the center as seen on Figure 1.
Figure 1: Measuring the length of the rod in order to confirm that it is clamped at the center.
A small amount of the rosin was placed on a piece of leather cloth or chamois skin. Gripping the rod with the rosined leather, it was pulled toward the end of the rod as seen on Figure 2.
Figure 2: Stroking the rod back and forth
The students avoided pulling the cloth completely off the rod because by doing so it will set up transverse waves in the rod and may break the glass tube. At first try, the students failed to do the right
METHODOLOGY
Two experiments were done last time due to some circumstances that made the class to lack time and to be late compared to the official class syllabus. The students were able to accomplished the job by equally dividing the time into two. The first experiment was about Kundt’s tube. In this experiment, longitudinal sound waves will be produced in a metal rod and an air column. Using the properties of wave motion , the frequency of the sound and the speed of sound in the rod can be determined.
For this experiment setup, following materials are needed such as a Kundt's tube apparatus, a meter stick, a piece of cloth, a thermometer, rosin, and lycopodium powder.
This experiment was done fast because of the fact that some of the procedures like placing a thin layer of lycopodium powder at least two millimetres wide as uniformly as possible inside the tube along its entire length was done already for us by the laboratory assistants. Then, a stopper was inserted in the end of the tube. Then, with the rod securely clamped at its center, the glass tube was positioned so that the disk on the end of the rod is a few centimeters within the tube and centered with respect to the sides. Before proceeding, the rod was confirmed to be at the right position by measuring the rod and make sure that it was clamped at the center as seen on Figure 1.
Figure 1: Measuring the length of the rod in order to confirm that it is clamped at the center.
A small amount of the rosin was placed on a piece of leather cloth or chamois skin. Gripping the rod with the rosined leather, it was pulled toward the end of the rod as seen on Figure 2.
Figure 2: Stroking the rod back and forth
The students avoided pulling the cloth completely off the rod because by doing so it will set up transverse waves in the rod and may break the glass tube. At first try, the students failed to do the right
References: [1] R.A. Serway and J.W. Jewett, Physics for Scientists and Engineers, 6th Ed. (Thomson, Belmont, CA, 2004), pp. 100-102 [2] Beiser, Arthur, Concepts of Modern Physicss, 5th Ed., McGraw-Hill, 1995 [3] Halliday and Resnick, Fundamentals of Physics, 9th Ed., Wiley 2011 [4] Laboratory manual, General Physics 3, Department of Physics, Mapúa Institute of Technology [5] Padua, A., Practical and Explorational Physics, 2003