To remove a nut from an old rusty bolt, you apply a 100-N force to the

The most important barriers to diffusion today are physical features of Earth's surface.

nikdorinn [45]

Answer:

False

Explanation:

Physical features of earth's surface like mountains, deserts and oceans are not the barriers in today's modern world. Technological improvements in the transportation and communication has removed these barriers. So they are not barriers anymore.

7 0

3 years ago

A submarine is 2.99 ✕ 102 m horizontally from shore and 1.00 ✕ 102 m beneath the surface of the water. A laser beam is sent from

Vsevolod [243]

Answer:

a The diagram of the situation is shown on the first uploaded image

b the angle of incidence beam striking the water is $\theta = 49.63^o$

c the angle of refraction beam striking the water is $r = 59.7^o$

d The angle the refracted beam make with respect to the horizontal is $= 30.3^o$

e The height of the target above sea level is

$h= 125.05m$

Explanation:

From the diagram we see that the angle of the beam striking the water is

$tan \theta = \frac{100}{85}$

$\theta = tan^{-1}(\frac{100}{85} )$

$= 49.63^o$

According to Snell's law

$\mu_{water} *sin(i) = \mu_{air} *sin(r)$

Where $\mu_{water }$ is the refractive index of water = 1.333

$i$ is the angle of incidence

$\mu_{air}$ is the refractive index of air = 1

r is the angle of refraction

Substituting values accordingly

$1.33 * sin (40.37) = 1 * sin(r)$

Making r the subject of the formula

$r = sin^{-1}(\frac{1.333 *sin(40.37)}{1})$

$= 59.7^o$

looking at the diagram we can see that to obtain the angle the refraction beam makes with the horizontal by subtracting the angle refraction from 90°

i.e $90 -59.7 = 30.3$ °

From the diagram we see that the height target above sea level can be obtained by this relation

$tan \theta = \frac{h}{214}\\$

Where h is the is the height

$tan(30.3) = \frac{h}{214}$

$h = 214 * tan (30.3)$

$=125.05m$

4 0

3 years ago

Heart cells must contract simultaneously to move blood.

krek1111 [17]

Answer:

Explanation:

The heart cells must contract simultaneously to move blood.

This means that it needs to act fast and efficiently.

Therefore, the connections among heart cells are characterized by :

having many branches
having many communicating junctions

The correct option should be <u>A</u>

4 0

2 years ago

Read 2 more answers

Which of the following statements is true?

erastova [34]

Hi there!

Question - Which of the following statements is true?

Answer - C. You are exposed to nuclear radiation every day.

Why - "radiation in the form of elementary particles emitted by an atomic nucleus, as alpha rays or gamma rays, produced by decay of radioactive substances or by nuclear fission."

6 0

3 years ago

What is the best explanation for why, on average, children playing inside a

Anestetic [448]

Answer:

In a house there is a lot less space so there is no where for the sound to travel, but if you are outside there is a lot more space so therefore, the sound can travel anywhere.

Explanation:

5 0

3 years ago