Features of Elements

In aviation, it is helpful for pilots to know the cloud celling, which is the distance between the ground and lowest cloud. The

MissTica

Answer:

0.27km

Explanation:

tanA= $\frac{a}{b}$

a=btanA

a=(0.75km)tan20

=0.27km

3 0

3 years ago

According to newtons third law of motion action nd reaction forces are equal in magnitudes nd opposite in direction but they do

snow_lady [41]

Because the action and the reaction forces act on different objects

Explanation:

Newton's third law of motion states that:

<em>"When an object A exerts a force on an object B (action), then object B exerts an equal and opposite force (reaction) on object A"</em>

From the statement above, we clearly see that the two forces mentioned in the law act on different objects. In fact, the action is exerted on object B, while the reaction is exerted on object A.

When we are considering the free-body diagram of an object, we just represent all the forces acting on that object, but not the forces exerted on other objects: this means that the action and the reaction never appear in the same free-body diagram of the same object, so they do not cancel out, simply because they are applied to different objects.

Learn more about Newton's third law:

brainly.com/question/11411375

#LearnwithBrainly

6 0

3 years ago

An object has a mass of 20kg, what is its weight on Earth?

umka2103 [35]

Answer:

The formula is W=mg.

W=20×10=200.

5 0

3 years ago

Read 2 more answers

Given that two vectors A = 5i-7j-3k, B = -4i+4j-8k find A×B

WARRIOR [948]

$\textbf{A}×\textbf{B}= 68\hat{\textbf{i}} + 52\hat{\textbf{j}} - 8\hat{\textbf{k}}$

Explanation:

Given:

$\textbf{A} = 5\hat{\textbf{i}} - 7\hat{\textbf{j}} - 3\hat{\textbf{k}}$

$\textbf{B} = -4\hat{\textbf{i}} + 4\hat{\textbf{j}} - 8\hat{\textbf{k}}$

The cross product $\textbf{A}×\textbf{B}$ is given by

$\textbf{A}×\textbf{B} = \left|\begin{array}{ccc}\hat{\textbf{i}} & \hat{\textbf{j}} & \hat{\textbf{k}} \\\:\:5 & -7 & -3 \\ -4 & \:\:4 & -8 \\ \end{array}\right|$

$= \left|\begin{array}{cc}-7 & -3\\\:4 & -8\\ \end{array}\right|\:\hat{\textbf{i}}\:+\:\left|\begin{array}{cc}-3 & \:\:5\\-8 & -4\\ \end{array}\right|\:\hat{\textbf{j}}\:+\: \left|\begin{array}{cc}\:\:5 & -7\\-4 & \:\:4\\ \end{array}\right|\:\hat{\textbf{k}}$

$= 68\hat{\textbf{i}} + 52\hat{\textbf{j}} - 8\hat{\textbf{k}}$

5 0

3 years ago

A ray of light crosses a boundary between two transparent materials. The medium the ray enters has a larger optical density. Whi

Tpy6a [65]

Answer:

The wavelength of the light decreases as it enters into the medium with the greater optical density.

The frequency of the light remains constant as it transitions between materials.

Explanation:

- When a ray of light crosses a boundary between two different materials, it undergoes refraction: the ray changes direction, and it also changes speed, according to the relationship:

$v=\frac{c}{n}$

where v is the speed of the ray of light in the material, c is the speed of light in a vacuum, n is the index of refraction of the material, which is larger for a medium with larger optical density. So, from the equation, we see that the larger the optical density, the smaller the speed of the wave.

- The frequency of the light does not depend on the properties of the medium, so it remains unchanged: therefore the statement

The frequency of the light remains constant as it transitions between materials.

is correct.

- Moreover, the wavelength of the ray of light is related to the speed and the frequency by the equation

$\lambda=\frac{v}{f}$

where v is the speed and f the frequency. Since we have seen that v decreases and f remains constant, this means that the wavelength decreases as well, so the statement

The wavelength of the light decreases as it enters into the medium with the greater optical density.

is also correct.

5 0

3 years ago