Two coherent sources of radio waves, A and B, are 5.00 meters apart. Each source emits waves with wavelength 6.00 meters. Consider points along the line connecting the two sources. Required:a. At what distance from source A is there constructive interference between points A and B?b. At what distances from source A is there destructive interference between points A and B?

a

b

Explanation:

From the question we are told that

     Their distance apart is  

      The  wavelength of each source wave

Let the distance from source A  where the construct interference occurred be z

Generally the path difference for constructive interference is

Now given that we are considering just the straight line (i.e  points along the line connecting the two sources ) then the order of the maxima m =  0

  so

=>    

=>    

Generally the path difference for destructive  interference is

=>        

=>        

substituting values

=>      

So  

and

=>  

=>    

answer: 31, 5556. 952 seconds

3. dark matter

empty space could also be a simple vacuum