Answer:
Yes, the answer to the question is correct
Answer:
The frequencies are
Explanation:
From the question we are told that
The length of the ear canal is
The speed of sound is assumed to be
Now taking look at a typical ear canal we see that we assume it is a closed pipe
Now the fundamental harmonics for the pipe(ear canal) is mathematically represented as
substituting values
Also the the second harmonic for the pipe (ear canal) is mathematically represented as
substituting values
Given that sound would be loudest in the pipe at the frequency, it implies that the child will have an increased audible sensitivity at this frequencies
Relativistic energy is the energy that is in the form of mass, E=mc² where c=speed of light, therefore the energy=0.3*(3*10^8)² =2.7*10^16 J
Answer:
v = 9.04 m / s
Explanation:
For this exercise we can use the relation that the work of the non-conservative force (friction) is equal to the variation of the mechanical energy of the system.
W = Em_f - Em₀ (1)
Starting point. Lower slope
Em₀ = K = ½ m v²
highest point. Where is the skier at a height h
Em_f = U = m g h
The work of rubbing
W = -fr x
the negative sign is because the friction force opposes the movement.
Let's set a reference system where the x axis is parallel to the slope and the y axis is perpendicular
let's use trigonometry to break down the weight
cos θ = W_y / W
sin θ = Wₓ / W
W_y = W cos θ
Wₓ = W sin θ
Y axis
N - Wₓ = 0
N = mg sin θ
X axis
fr = m a
the friction force has the expression
fr = μ N
fr = μ mg sin θ
we look for the job
W = - μ mg sin θ x
where x is the distance along the slope
we substitute in 1
-μ mg sin θ x = mg h - ½ m v²
let's use trigonometry to find the distance x
tan 30 = h / x
x = h / tan 30
we substitute
- = m gh - ½ m v²
we use
tan 30 = sin30 / cos30
v² = 2g h + 2 μ g h cos 30
v =
let's calculate
v =
v = 9.04 m / s
Answer:
t = 9.16 10⁻⁸ m
Explanation:
In this exercise we fear a case of interference by reflection,
We have two aspects
* when the light ray passes from the air to the TiO2 that has a higher refraction start, the reflected ray has a phase change of 180º
* when the beam is inside the material its wavelength changes
λₙ = λ₀ / n
with these two done the equation for destructive interference remains
2t = m λₙ
2nt = m λ₀
They ask us for the thickness t of the film for m = 1
t = m λ₀ / 2n
let's calculate
t =
t = 9.16 10⁻⁸ m