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3 years ago

Which describes why people on earth can see light from the stars in the sky that are so far away?

Physics

1 answer:

balandron [24]3 years ago

3 0

Choice-C is a correct statement.

Each of the other choices combines elements of truth
with elements of hogwash.

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The local newspaper has published the passage below. Last week, scientists released incredible images of aurora australis, known

OverLord2011 [107]

Answer:

The statement as aurora australis known as northern lights is incorrect. As the designation of aurora australis is for the southern lights i.e. which occur in the southern hemisphere.

Explanation:

Aurora or natural lights is a phenomenon that occurs at the poles of the Earth due to interaction between the Earth's magnetic field and cosmic rays. This interaction results in the beautiful display of colors on both poles. These are named, aurora borealis or aurora australis depending on their geographical location. If they occur on the northern pole they are termed as aurora borealis while those occurring on the southern pole are named aurora australis.

6 0

3 years ago

Read 2 more answers

You have been hired to design a spring-launched roller coaster that will carry two passengers per car. The car goes up a 13-m-hi

Andrew [12]

Answer:

22.15 N/m

Explanation:

As we know potential energy = m*g*h

Potential energy of spring = (1/2)kx^2

m*g*h = (1/2)kx^2

Substituting the given values, we get -

(400)*(9.8)*(10) = (0.5)*(k)*(2.0^2)

k = 39200/2.645

k = 19600 N/m

For safety reasons, this spring constant is increased by 13 % So the new spring constant is

k = 19600 * 1.13 = 22148 N/m = 22.15 N/m

3 0

3 years ago

A Level is set up midway between two wood hubs that are about 300 ft. apart. The rod reading on hub A is 9.09 ft. and the readin

Zarrin [17]

Answer:

<em>The correct difference is 3.44 ft</em>

Explanation:

The correct difference is given as

D=R_A-R_B

D=9.09-5.65

D=3.44 ft

4 0

3 years ago

An empty jar is pushed open-side down into water so that trapped air cannot escape. As it is pushed deeper, the buoyant force on

Pavlova-9 [17]

As it is pushed deeper, the buoyant force on the jar will decrease. The correct option is B

<h3>What is buoyant force ?</h3>

The upward force applied to an object that is fully or partially submerged in a fluid is known as the buoyant force. Upthrust is another name for this upward thrust. A body submerged partially or completely in a fluid appears to shed weight, or to be lighter, due to the buoyant force.

The fluid under which an object is submerged exerts pressure, which is what generates the buoyancy force. Because a fluid's pressure rises with depth, the buoyancy force is always upward.

To know more about buoyant force you may visit the link:

brainly.com/question/21990136

#SPJ4

3 0

1 year ago

An automobile is traveling away from Jill and towards Jack. The horn is honking, producing a sound wave.

wlad13 [49]

Answer:

a. The sound will travel at the speed to both Jill and Jack

b. Jack

Explanation:

a. Doppler effect describes how the frequency of a sound wave changes with regards to an observer that has relative motion to the sound source;

The Doppler effect is given by the following formula;

For a sound that is moving away, as observed by Jill, we have;

$f' = \dfrac{(v - v_0)}{(v + v_s)} \cdot f = \dfrac{v }{(v + v_s)} \cdot f$

For approaching sound, as observed by Jack, we have;

$f' = \dfrac{(v + v_0)}{(v - v_s)} \cdot f = \dfrac{v }{(v - v_s)} \cdot f$

Where;

f = The sound wave's actual frequency

f' = The frequency of the moving sound to the observer

v = The speed of the sound wave

v₀ = The observer's velocity = 0

$v_s$ = The velocity of the source (the automobile honking) of the sound wave

From the above equation, we have that the speed of sound, 'v', is the same to both the source, and the observer although the frequency, and therefore, the wavelength of the sound alternatively increases or decreases

b. From the Doppler effect equation, the person who will hear the highest frequency is given by the formula for the frequency when the sound is approaching the observer, which has the lower denominator

Therefore, given that the automobile is travelling towards Jack, jack will hear the higher frequency

5 0

3 years ago