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Aliun [14]
2 years ago
10

To make sure you understand how to use the equation, suppose that there are 1000 habitable planets in our galaxy, that 1 in 10 h

abitable planets has life, that 1 in 4 planets with life has at some point had an intelligent civilization, and that 1 in 5 civilizations that have ever existed is in existence now. How many civilizations would exist at present?
Physics
1 answer:
krok68 [10]2 years ago
5 0

Answer:

5

Explanation:

Number of habitable planets = 1000

Fraction of planet with life = 1/10

Fraction of planet with life and civilization (before) = 1/4

Fraction of planet with life and civilization (now) =1/5

Therefore multiplying we have:

1000×1/10×1/4×1/5 = 5

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Answer:

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What velocity does a 2kg mass have when its kinetic energy is 16 J
alexandr402 [8]
We can use the equation for kinetic energy, K=1/2mv².
Your given variables are already in the correct units, so we can just plug in the variables and solve for v. 

K = 1/2mv²
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Hope this is helpful!
7 0
3 years ago
Which are characteristics of electromagnetic waves?check all that apply.
emmainna [20.7K]

Correct choices are marked in bold:

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travel only through matter  --> FALSE; electromagnetic waves can also travel through vacuum

travel only through space  --> FALSE, electromagnetic waves can also travel through matter

can bend around objects  --> TRUE, this is what happens for instance when diffraction occurs: electromagnetic waves are bended around obstacles or small slits

move by particles bumping into each other  --> FALSE, electromagnetic waves are oscillations of electric and magnetic fields, so no particles are involved

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8 0
3 years ago
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Keith_Richards [23]

Answer:

Earth is nearest the Sun in July and farthest away in July.

Explanation:

3 0
3 years ago
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