ch 4 hw

distinguish between partials harmonics and overtones

partials, harmonics and overtones are all components of sound. a partial includes the fundamental plus the overtone. and overtone has a frequency greater than the fundamental, a harmonic is a mode of vibration whose frequency is a whole number multiple of the fundamental frequency

can a single break a wineglass by singing loudly?

perhaps

In fig 4.4 do the solid curves or dashed lines represent a higher Q?

the solid line has a higher Q, the higher the damping, the less abrupt the phase change is, and there for the lower the Q.

a nylon guitar string 65 cm long has a mass of 8.3 x 10^-4 kg.m and the tension is 56 N. find the frequencies of the first four partials

v=260 m/s f1= 200 Hz f2= 400 Hz f3= 600 Hz f4= 800 Hz

determine the frequencies of the fundamental and first overtone (second partial) for the following. neglect the end corrections -16 ft open ended -16 ft one end open one end closed

35 Hz, 70 Hz 17.5 Hz, 52.5 Hz

a pipe with one open and one closed end has its resonance at 200 Hz. What are the frequencies of its next two resonances?

3f1= 600Hz 5f1= 1000Hz

find the difference in the fundamental frequency calculated with and without the end correction of an open end pipe 2m long and 10 cm in diameter

85.7 Hz, 83.3 Hz difference = 2.4 Hz

in order to lower the helmholtz resonances of a guitar, would you make the sound hole larger or smaller

a larger sound produces a greater neck area, and therefore a higher resonance, a smaller neck area produces a lower frequency.

what is acoustic impedance?

acoustic impedance is it the ratio of sound pressure to the volume of velocity

to excite a singing rod in its fundamental mode, where should you hold it? where should you stroke it

hold at the center of the rod where the node is, stroke it towards the ends

what does n equal in fig 4.5 d? how many wavelengths = L?

in fig 4.5 d n= 11 (11 nodes), L=5 wavelengths

what is the main function of a piano soundboard?

radiation from a vibrating string is greatly enhanced by the sympathetic vibration of the soundboard

if you blow over the ends of 2 pipes, one with the other end closed and one with it open, which pipe will give the tone of lower pitch?

the closed end pipe will be one octave lower bc it vibrates with hard the fundamental frequency

write a definition of resonance and give examples

when a vibrator is driven by a force that oscillates at a frequency at or near the natural frequency of the vibrator, a relatively large amplitude results -child on a swing -pendulum -standing waves in a pipe or string