To practice Problem-Solving Strategy 17.1 for wave interference problems. Two loudspeakers are placed side by side a distance d = 4.00 m apart. A listener observes maximum constructive interference while standing in front of the loudspeakers, equidistant from both of them. The distance from the listener to the point halfway between the speakers is l = 5.00 m . One of the loudspeakers is then moved directly away from the other. Once the speaker is moved a distance r = 60.0 cm from its original position, the listener, who is not moving, observes destructive interference for the first time. Find the speed of sound v in the air if both speakers emit a tone of frequency 700 Hz .

Complete Question

The compete question is shown on the first uploaded question

The speed is    

Explanation:

From the question we are told that

   The  distance of separation is  d =  4.00 m  

  The distance of the listener to the center between the speakers is  I =  5.00 m

  The change in the distance of the speaker is by

    The frequency of both speakers is

Generally the distance of the listener to the first speaker is mathematically represented as

Generally the distance of the listener to second speaker at its new position is  

Generally the path difference between the speakers is mathematically represented as

Here is the wavelength which is mathematically represented as

=>    

=>      

=>      

Here n is the order of the maxima with  value of  n =  1  this because we are considering two adjacent waves

=>          

=>      

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.