Sound—energy<span> we can hear—travels only so far before it soaks away into the world around us. Until electrical </span>microphones<span>were invented in the late 19th century, there was no satisfactory way to send </span>sounds<span> to other places. You could shout, but that carried your words only a little further. You couldn't shout in New York City and make yourself heard in London. And you couldn't speak in 1715 and have someone listen to what you said a hundred years later! Remarkably, such things are possible today: by converting sound energy into electricity and information we can store, microphones make it possible to send the sounds of our voices, our music, and the noises in our world to other places and other times. How do microphones work? Let's take a closer look!</span>
        
             
        
        
        
To solve this problem we will apply the concept of frequency in a string from the nodes, the tension, the linear density and the length of the string, that is,

Here
n = Number of node
T = Tension
 = Linear density
 = Linear density
L = Length 
Replacing the values in the frequency and value of n is one for fundamental overtone



Similarly plug in 2 for n for first overtone and determine the value of frequency



Similarly plug in 3 for n for first overtone and determine the value of frequency



 
        
             
        
        
        
Answer:
57.885.8 kg   weight of the container 
Explanation:
The volume of the balloon * density of water = buoyant force of balloon 
  volume of a sphere = 4/3 pi r^3 
                                    = 4/3 pi * (1.5)^3 = 14.14 m^3   <===balloon volume
Now,   find the buoyant force on the container ALONE ....
              5.8 * 2.6 * 2.8  * 1027  = 43 364  kg   <=====  buoyant force 
Now add the buoyant force of the balloon to find the weight 
              43 364  +   14.14 * 1027 = 57885.8   kg
 
        
             
        
        
        
912.
outer ear:
pinna 
ear canal
middle ear:
ossicles and ear drum
inner ear:
semcircular canals
cochlea
auditory nerve
13.
frequency = wavespeed ÷ wavelength
14. 
if frequency increases you would experience a higher pitch in sound
15.
humans can hear 20Hz to 20kHz
16.
The Doppler effect is the change in frequency or wavelength of a wave for an observer who is moving relative to the wave source. Can be used for machines measuring speed via doppler effect.
17.
Doppler in hospitals can be used for ultrasound to provide images for diagnosis and monitoring.