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3 years ago

Why are the stars that appear in the night sky not visible during the day?

Physics

1 answer:

xxTIMURxx [149]3 years ago

6 0

Because the sun is not hitting the light on them and there not as bright like when we see them when it's dark.

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A heavy dart and a light dart are launched vertically by identical ideal springs. Both springs were initially compressed by the

sveticcg [70]

Answer:

Explanation:

8 0

4 years ago

A ray of light passes from air into a block of clear plastic. How does the angle of incidence in the air compare to the angle of

andre [41]

Answer:

The angle of incidence is greater than the angle of refraction

Explanation:

Refraction occurs when a light wave passes through the boundary between two mediums.

When a ray of light is refracted, it changes speed and direction, according to Snell's Law:

$n_1 sin \theta_1 = n_2 sin \theta_2$

where :

$n_1$ is the index of refraction of the 1st medium

$n_2$ is the index of refraction of the 2nd medium

$\theta_1$ is the angle of incidence (the angle between the incident ray and the normal to the boundary)

$\theta_2$ is the angle of refraction (the angle between the refracted ray and the normal to the boundary)

In this problem, we have a ray of light passing from air into clear plastic. We have:

$n_1=1.00$ (index of refraction of air)

$n_2=1.50$ approx. (index of refraction in clear plastic)

Snell's Law can be rewritten as

$sin \theta_2 =\frac{n_1}{n_2}sin \theta_1$

And since $n_2>n_1$ , we have

$\frac{n_1}{n_2}$

And so

$\theta_2$

Which means that

The angle of incidence is greater than the angle of refraction

6 0

3 years ago

Which of the following is inversely proportional to the gravitational force between two masses?

Mrrafil [7]

It is D, the distance between each object squared. We get this from solving for the force of gravity, which is

F = G((m1*m2)/(r^2)).

Here, you can see that the masses of the two objects are divided by their total distance apart from each other (r) squared.

6 0

3 years ago

A penny is kicked horizontally off the roof of a 10-story building (33.3 m high) and lands 52 m away on the ground. A) what is t

yanalaym [24]

A) The penny was kicked horizontally off the building. By this very statement, the penny had 0 initial vertical velocity.

B) Apply the following kinematics equation to the penny's vertical motion:

D = Vt + 0.5At²

D = vertical distance traveled, t = time, V = initial vertical velocity, A = vertical acceleration

Given values:

D = 33.3m, V = 0m/s, A = 9.81m/s²

Plug in and solve for t:

33.3 = 4.905t²

t = 2.61s

C) The penny fell for 2.61 seconds, therefore it moved horizontally for 2.61 seconds.

v = x/t

v = horizontal velocity, x = horizontal distance traveled, t = time

Given values:

x = 52m, t = 2.61s

Plug in and solve for v:

v = 52/2.61

v = 19.9m/s

D) Let's calculate the penny's vertical speed right before it hits the ground:

v = at

v = final vertical speed, a = vertical acceleration, t = time

Given values:

a = 9.81m/s², t = 2.61s

Plug in and solve for v:

v = 9.81(2.61)

v = 25.6m/s

Use the Pythagorean theorem to find the final speed:

V = √(Vx²+Vy²)

V = final speed, Vx = final horizontal speed, Vy = final vertical speed

Given values:

Vx = 19.9m/s, Vy = 25.6m/s

Plug in and solve for V:

V = √(19.9²+25.6²)

V = 32.4m/s

5 0

3 years ago

Mr. Llama walked from his house to the bus stop. The bus stop is 2 miles from his house. He returned back to his house from the

Hoochie [10]

Answer:

Displacement of Mr. Llama: Option D. 0 miles.

Explanation:

The magnitude of the displacement of an object is equal to the distance between its final position and its initial position. In other words, as long as the initial and final positions of the object stay unchanged, the path that this object took will not affect its displacement.

For Mr. Llama:

Final position: Mr. Llama's house;
Initial position: Mr. Llama's house.

The distance between the final and initial position of Mr. Llama is equal to zero. As a result, the magnitude of Mr. Llama's displacement in the entire process will also be equal to zero.

7 0

4 years ago