A. The vibrations of the fields are perpendicular to the direction in which the wave moves.
The question is incomplete. The complete question is :
Two loudspeakers are placed 1.8 m apart. They play tones of equal frequency. If you stand 3.0 m in front of the speakers, and exactly between them, you hear a minimum of intensity. As you walk parallel to the plane of the speakers, staying 3.0 m away, the sound intensity increases until reaching a maximum when you are directly in front of one of the speakers. The speed of sound in the room is 340 m/s.
What is the frequency of the sound?
Solution :
Given :
The distance between the two loud speakers, 
The speaker are in phase and so the path difference is zero constructive interference occurs.
At the point 
, the speakers are out of phase and so the path difference is 
Therefore,
Thus the frequency is :
Hz
The answer is D, talking more loudly or quietly.
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An expressive voice can bring totally different meaning to what you are saying. If you speak in a monotone voice, you are implying that you do not care about what you are saying or what the other person is talking about. If you speak expressively with some parts quieter or louder to make a point, it lets the listener know that you care about what you are saying and you care about what they have to say too. You can also emphasize a point by speaking louder or indicate that something is not as important by speaking softer.</span>
I think the correct answer from the choices listed above is option A. The kinetic energy after the perfectly inelastic collision would be zero Joules. <span>A </span>perfectly inelastic collision<span> occurs when the maximum amount of kinetic energy of a system is lost. Hope this answers the question.</span>
