Answer:
200 nm is the thinnest film that produces a strong reflection for green light with a wavelength of 500 nm
Explanation:
If two reflected waves interfere constructively ,strong reflection is produced. Two reflected waves will experience a phase change
For constructive interference

for thinnest film m=1
refractive index should be taken for film n=1.25
thickness of the thinnest film is

<span>A. No sound is heard
A*sin(wt)+(-A)*sin(wt)=0 - no sound
</span>
Answer:

Explanation:
The index of refraction is equal to the speed of light c in vacuum divided by its speed v in a substance, or
. For our case we want to use
, which for our values is equal to:

Which we will express with 3 significant figures (since a product or quotient must contain the same number of significant figures as the measurement with the <em>least</em> number of significant figures):

Answer:
12 m
Explanation:
The object is in uniformly accelerated motion, so the distance covered can be found using the following suvat equation:

where
s is the distance
u is the initial velocity
t is the time
a is the acceleration
For this problem,

and
u = 0, since we are considering the first second of motion
So, substituting t = 1 s, we find

Answer:
75degree don't forget wind and gravity force pulling down