Solar energy is one of the renewable energy sources that is invested around the world because of its large potential. the sun as a free source can sometimes bring a drawback. one of the drawbacks is that it cannot be harnessed when storms or rains are present in the weather. it is also expensive and young.
Answer:
the thickness of the film for destructive interference is 1 cm
Explanation:
We can assume that the radar wave penetrates the layer and is reflected in the inner part of it, giving rise to an interference phenomenon of the two reflected rays, we must be careful that the ray has a phase change when
* the wave passes from the air to the film with a higher refractive index
* the wavelength inside the film changes by the refractive index
λ = λ₀ / n
so the ratio for destructive interference is
2 n t = m λ
t = m λ / 2n
indicate that the wavelength λ = 2 cm, suppose that the interference occurs for m = 1, therefore it is thickness
t = 1 2/2 n
t = 1 / n
where n is the index of refraction of the anti-reflective layer. As they tell us not to take into account the change in wavelength when penetrating the film n = 1
t = 1 cm
So the thickness of the film for destructive interference is 1 cm
To solve this problem, let us consider that the Earth is the
origin, the initial reference point. Therefore the speed of rocket plus the
missile would be 0.8 C
Now after the rocket had moved away from Earth, it fired a missile
at a speed of 0.7 C. Now the reference made to this is relative to the rocket.
We have established that our initial reference point is the Earth, therefore
the real speed of the missile with reference to Earth is:
Speed of missile relative to Earth = 0.8 C + 0.7 C
Speed of missile relative to Earth = 1.5 C
Answer is:
<span>A</span>
Option number three is correct energy can be transformed and moved and released but it can't be destroyed and doesn't disappear.
