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2 years ago

12

5. Tại sao khi lặn ta luôn cảm thấy tức ngực và càng lặn sâu thì cảm giác tức ngực càng tăng? A. Ap suất của nước giảm B. Ap s

uất không khí tăng C. Ap suất không khí giảm D. Ap suất của nước tăng

1 answer:

natali 33 [55]2 years ago

7 0

Answer:

c and d

Explanation:

obviously kksxsxksxkskxkskxksxksxsxsxsxsxsxsxs

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A laser emits two wavelengths (λ1 = 420 nm; λ2 = 630 nm). When these two wavelengths strike a grating with 450 lines/mm, they pr

Westkost [7]

A) Order of the first laser: 3, order of the second laser: 2

B) The overlap occurs at an angle of $34.9^{\circ}$

Explanation:

A)

The formula that gives the position of the maxima (bright fringes) for a diffraction grating is

$d sin \theta = m \lambda$

where

d is spacing between the lines in the grating

$\theta$ is the angle of the maximum

m is the order of diffraction

$\lambda$ is the wavelength of the light

For laser 1,

$d sin \theta = m_1 \lambda_1$

For laser 2,

$d sin \theta = m_2 \lambda_2$

where

$\lambda_1 = 420 nm\\\lambda_2 = 630 nm$

Since the position of the maxima in the two cases overlaps, then the term $d sin \theta$ on the left is the same for the two cases, therefore we can write:

$m_1 \lambda_1 = m_2 \lambda_2\\\frac{m_1}{m_2}=\frac{\lambda_2}{\lambda_1}=\frac{630}{420}=\frac{3}{2}$

Therefore:

$m_1 = 3$

$m_2 = 2$

B)

In order to find the angle at which the overlap occurs, we use the 1st laser situation:

$d sin \theta = m_1 \lambda_1$

where:

N = 450 lines/mm = 450,000 lines/m is the number of lines per unit length, so the spacing between the lines is

$d=\frac{1}{N}=\frac{1}{450,000}=2.2\cdot 10^{-6} m$

$m_1 = 3$ is the order of the maximum

$\lambda_1 = 420 nm = 420\cdot 10^{-9} m$ is the wavelength of the laser light

Solving for $\theta$ , we find the angle of the maximum:

$sin \theta = \frac{m_1 \lambda_1}{d}=\frac{(3)(420\cdot 10^{-9})}{2.2\cdot 10^{-6}}=0.572$

So the angle is

$\theta=sin^{-1}(0.572)=34.9^{\circ}$

Learn more about diffraction:

brainly.com/question/3183125

#LearnwithBrainly

5 0

3 years ago

What environmental factors affect sound?

Mariana [72]

Answer:

Here are 5:

Distance from source to receiver

Wind speed and direction

Wind gradients

Temperature gradients

Atmospheric attenuation

and there are many more...

Hope that was helpful.Thank you!!!

7 0

2 years ago

If the load distance of a lever is 30 cm and the effort distance is 60 cm, calculate the amount of effort required to lift a loa

vladimir2022 [97]

Here,

Load distance (Ld) = 30 cm

Effort distance (Ed) = 60 cm

Load (L) = 200N

Effort (E) = ?

Now, By using formula,

or, E * Ed = L * Ld

or, E * 60 = 200 * 30

or, E = 6000/60

◆ E = 100N

This is a Right answer...

I hope you understand...

7 0

2 years ago

A 1000-kg car is driving toward the north along a straight horizontal road at a speed of 20.0 m/s. The driver applies the brakes

Nitella [24]

Answer:

The value of F= - 830 N

Since the force is negative, it implies direction of the force applied was due south.

Explanation:

Given data:

Mass = 1000-kg

Distance, d = 240 m

Initial velocity, v1 = 20.0 m/s

Final velocity, v2 = 0 (since the car came to rest after brake was applied)

v2²= v1² + 2ad (using one of the equation of motion)

0= 20² + (2 x a x 240)

0= 400 + 480 a

a = - 400/480

a = - 0.83 m/s²

Then, imputing the value of a into

F = ma

F = 1000 kg x ( - 0.83 m/s²)

F= - 830 N

The car was driving toward the north, and since the force is negative, it implies direction of the force applied was due south.

3 0

2 years ago

An object with a lot of mass has ____________.

aleksley [76]

C. a lot of inertia.............................. :-)

3 0

2 years ago