Question

# 1- Determine the length of a wind instrument, assuming that it is modeled as a closed tube and that the lowest

sound that it can play has a frequency of 104 Hz

Hz ? The speed of sound in air is 343m/s

m/s.

**Express your answer to two significant figures and include the appropriate units.**

2- The A string on a violin has a fundamental frequency of 440 Hz

Hz . The length of the vibrating portion is 35 cm

cm , and it has a mass of 0.39 g

g .

Under what tension must the string be placed?

**Express your answer using two significant figures.**

3- a-What is the beat frequency if middle C (262 Hz) and C#C# (277 Hz) are played together?

b- What if each is played two octaves lower (each frequency reduced by a factor of 4)?

4- Two violin strings are tuned to the same frequency, 294 Hz

Hz . The tension in one string is then decreased by 2.3 %

% .What will be the beat frequency heard when the two strings are played together? [*Hint*: Recall the equation v=√FT/m/L

**Express your answer to two significant figures and include the appropriate units.**

**5- **A certain dog whistle operates at 23.2 kHz

kHz , while another (brand X) operates at an unknown frequency.If humans can hear neither whistle when played separately, but a shrill whine of frequency 5100 Hz

Hz occurs when they are played simultaneously, estimate the operating frequency of brand X.

#### Top Answer

1) Length, L = 82 cm = 0.82 m. 2) Tension, T = 105.7 N. 3) Beat frequencies... View the full answer