Answer: because ν = velocity/λ where ν and λ are the frequency and wavelegth of the wave.
Explanation: In order to explain this problem we have to consider the relationship between frequency and wavelengths which are related by the velocity of the wave as follows ν*λ=v where ν and λ are the frequency and wavelegth of the wave. These parameters have an inverse proportionality.
Then, ν = velocity/λ
A surface in which is flat or very soft to the touch and reduces splinters or anything sticking out, having an surface which does not have lumps, or indentations.
Answer:
The volume of the submerged part of her body is 
Explanation:
Let's define the buoyant force acting on a submerged object.
In a submerged object acts a buoyant force which can be calculated as :
ρ.V.g
Where ''B'' is the buoyant force
Where ''ρ'' is the density of the fluid
Where ''V'' is the submerged volume of the object
Where ''g'' is the acceleration due to gravity
Because the girl is floating we can state that the weight of the girl is equal to the buoyant force.
We can write :
(I)
Where ''W'' is weight
⇒ If we consider ρ = 
(water density) and 
and replacing this values in the equation (I) ⇒
ρ.V.g = 610N
(II)
The force unit ''N'' (Newton) is defined as
Using this in the equation (II) :
We find that the volume of the submerged part of her body is
Answer:
t< 75 nm
Explanation:
A soap bubble is a thin film where when the beam enters the film it has a 180º phase change due to the refractive index and the wavelength changes between
λ = λ₀ / n
In the case of constructive interference in the curve of the spherical film it is
2 nt = (m + ½) λ₀
Where t is the thickness of the film and n the refractive index that does not indicate that we use that of water n = 1.33, m is an integer. The thickness of the film for the first interference (m = 0) is
t = λ₀ / 4 n
A thickness less than this gives destructive interference.
Let's look for the thickness for the visible spectrum
Violet light λ₀ = 400 nm = 400 10⁻⁹ m
t₁ = 400 10⁻⁹ / 4 1.33
t₁ = 75.2 10-9 m
Red light λ₀ = 700 nm = 700 10⁻⁹ m
t₂ = 700 10⁻⁹ / 4 1.33
t₂ = 131.6 10⁻⁹ m
Therefore, for all wavelengths to have destructive interference, the thickness must be less than 75 10⁻⁹ m = 75 nm
b) a film like eta is very thin, it is achieved when gravity thins the pomp, but any movement or burst of air breaks it,
