Passage VII
A student conducted experiments to determine the relationship between the musical pitch (frequency) of a vibrating string and its length, tension, and mass density (mass per unit length of string).
Experiment 1
The student cut several lengths of steel strings having different diameters. The strings were weighed and their mass densities calculated. Specified lengths of the strings were hung from the ceiling. A block was suspended from the free end of each string, making the tension in the string equal to the suspended weight in newtons (N). Plucking the string caused it to vibrate, producing sound waves. The sound waves were detected by a microphone and displayed on the screen of an oscilloscope, where the fundamental frequency of vibration, in cycles per second, or hertz (Hz), could be measured. The results are presented in Table 1.
Experiment 2
The student repeated the procedure in Experiment 1, using strings made of nylon and gut and having different diameters. The results are presented in Table 2.
39. A student is given several nylon strings of identical vibrating length but unknown mass densities. The string with the highest mass density could be found by:
Your Answer is
Correct Answer is B
Explanation
Comparing trail 8 and trail 10, it can be found that when all other conditions are the same, the greater the mass density, the lower the frequency, so choose B