When person is observing destructive interference at 0.20 m distance from the equidistant position then we can say that path difference must be equal to half of the wavelength
now we will have

now we know that
y = 0.20 m
d = 2.4 m
L = 10 m
now here we have


now frequency of wave is given as


The time taken by traveler to cover the distance is,

Substitute the known values,

Therefore, the time taken by traveler to cover the distance is 89.3 s.
Answer:
Velocity (v) = 30 m/s
Wavelength = 35 m
frequency (f) = ?
now we know
v = wavelength * f
30 = 35 * f
therefore frequency = 0.857hertz
<u>[Reflection]</u>
- This occurs when light bounces off a surface (reflection is when light bounces off of something, a medium, but doesn't go through.)
- Best with a smooth surface (it is easiest for light to bounce off when the surface is smooth)
- If not for this behavior, mirrors wouldn't work (mirrors use reflection, if they did not you would not be able to see your <em>reflection</em>)
<u>[Refraction]</u>
- Light moves from one medium to another (when light moves from one medium to another, it refracts)
- Lenses in your glasses to bend light waves (refraction is all about bending light waves, so this option falls under this category)
- Microscopes and telescopes take advantage of this behavior of light (again, refraction is bending light waves. When you bend a light wave, it can make it easier to see [larger, smaller, etc] so this option is refraction)
- Light wave changes speed (light does not change speed when being reflected because it is in the same medium and just bouncing, but it refraction is changes mediums so it will bend and change speed)
[Note]
- Some of these can be figured out by knowing the definitions. For example, refraction is defined as "change in direction ... of any wave as a result of its traveling at different speeds at different points along the wave front" (Oxf/ord Languages)
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather