Based on the reading which statement is FALSE?

An object is thrown horizontally off of a cliff. While falling, what happens to the horizontal acceleration?

irga5000 [103]

There is no acceleration in the horizontal direction because the speed in that direction is constant. So it stays at zero.

8 0

3 years ago

The ability to navigate, hunt, and communicate by electric current in water most likely helps make up for the effect of dark, mu

fgiga [73]

The ability to navigate, hunt, and communicate by electric current in water most likely helps make up for the effect of vision. The answer to your question is VISION.

If fish live in a dark, murky water, that means that their sense of vision is affected. In dark, murky water they could not see anything. So, fish that lives in this kind of water developed the ability to o navigate, hunt, and communicate by electric current in water. This ability is known as electroreception. Among fish, electroreception is present in some sharks and rays, and electric eels.

I hope that this is the answer that you were looking for and it has helped you.

6 0

4 years ago

A ray of light traveling in air is incident on the surface of a block of clear ice (of index 1.309) at an angle of 25.5 ◦ with t

sergij07 [2.7K]

Answer: $135.29\º$

The figure attached will be helpful to understand the solution.

Here we see two cases, reflection and refraction of light.

According to the laws of reflection:

1. The incident ray, the reflected ray and the normal are in the same plane.

2. The angle of incidence is equal to the angle of reflection.

*Note the normal is perpendicular to the plane, with a $90\º$ angle with the surface

And this can be visualized in the figure, where the angle ${\theta}_{1}$ with which the incident ray hits the surface is equal to the angle with which this same ray is reflected.

On the other hand we have Refraction, a phenomenon in which the light bends or changes its direction when passing through a medium with a refractive index different from the other medium.

In this context, the Refractive index is a number that describes how fast light propagates through a medium or material.

According to Snell’s Law:

$n_{1}sin(\theta_{1})=n_{2}sin(\theta_{2})$ (1)

Where:

$n_{1}=1$ is the first medium refractive index (the air)

$n_{2}=1.309$ is the second medium refractive index (the ice)

$\theta_{1}=25.5\º$ is the angle of the incident ray

$\theta_{2}$ is the angle of the refracted ray

Now, firstly we have to find $\theta_{2}$ and then, by geometry, find $\alpha$ and $\beta$ which sum the angle between the reflected and the refracted light.

Finding $\theta_{2}$ from (1):

$(1)sin(25.5\º)=(1.309)sin(\theta_{2})$

$sin(\theta_{2})=0.328$

$\theta_{2}=arcsin(0.328)$

$\theta_{2}=19.201\º$ (2)

Remembering that the Normal makes a $90\º$ angle with the surface, we can say:

$90\º=\theta_{1}+\beta$ (3)

Finding $\beta$ :

$\beta=90\º-25.5\º=64.5\º$ (4)

Doing the same with $\theta_{2}$ and $\alpha}$ :

$90\º=\theta_{2}+\alpha$ (5)

Finding $\alpha$ :

$\alpha=90\º-19.201\º=70.79\º$ (6)

Adding both angles (4) and (6):

$\alpha+\beta=70.79\º+64.5\º$ (7)

$\alpha+\beta=135.29\º$ >>>This is the angle between the reflected and the refracted light.

5 0

3 years ago

If an astronaut goes on a space walk outside the Space Station, she will quickly float away from the station unless she has a te

Strike441 [17]

Answer:

d. This statement is false. She and the Space Station share the same orbit and will stay together unless they are pushed apart.

Explanation:

In astronomy, orbit is simply a path of an object around another object in a space. That is, orbit is a path of a body that revolves around a gravitating center of mass. Examples of an orbit is are satellite around a planet, orbit around a center of galaxy, planet around the sun, and among others.

On the other hand, space station refers to a spacecraft that can support a group of human for long time in the orbit. Another names for space stations are orbital space station and orbital station.

Therefore, an astronaut goes on a space walk outside the Space Station shares the same orbit with the space station and they will stay together unless they are pushed apart.

4 0

3 years ago

Electron guns are used in X-ray tubes. The electrons are accelerated through a relatively large voltage and directed onto a meta

Paul [167]

Answer:

(a) Number of electrons per second strike the target is 3.125 x 10¹⁵.

(b) Charge that strikes the target in 0.750 s is 3.75 x 10⁻⁴ C .

Explanation:

(a) Let n be the number of electrons per second strike the target. We know that current (I) is given by the relation :

I = n x e

Here e is charge of electron.

Substitute 0.500 x 10⁻³ A for I and 1.6 x 10⁻¹⁹ C for e in the above equation.

0.500 x 10⁻³ = n x 1.6 x 10⁻¹⁹

n = 3.125 x 10¹⁵

(b) Let q be the charge that strikes the target. We know that :

q = I x t

Here I is current and t is time.

Substitute 0.500 x 10⁻³ A for I and 0.750 s for t in the above equation,

q = 0.500 x 10⁻³ x 0.750

q = 3.75 x 10⁻⁴ C

3 0

4 years ago