Answer to Question #28944 in Optics for kyana

Question

1)why when water passes a log in water a smooth area of water is created behind the log but when the same wave passes a blade of grass there is no smooth area of water created?
a. length of water waves is short in comparison to the size of the grass
b. length of water waves is short in comparison to the size of the log
c. shadow area is created by the blade of grass but no shadow is created by the log

2)an interference pattern is produced when
a a pattern of light &dark fringes id produced
b both constructive & destructive interference occur
c diffraction occurs
d. all above

3) as sunlight on a bubble, one wave length of blue light is reflected from the inner surface of the soap film another wavelength of Blue light if reflected from the outer surface as the waves superimpose they are one half wave length out phase.. what will we see on that spot off film?
a.yellow
b. very deep blue
c. no color
d. red