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Aliun [14]
3 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]3 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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A vector A⃗ has a magnitude of 40.0 m and points in a direction 20.0∘ below the positive x axis. A second vector, B⃗, has a magn
jolli1 [7]

The magnitude of the vector C is 96.32m

<h3>How to solve for the magnitude of vector c</h3>

Ax = AcosθA

= 40 cOS 20

= 37.59

Ay = AsinθA

-40sin20

= -13.68

Bx = B cos θ B

= 75Cos50

= 48.21

By = BsinθB

= 75sin50

= 57.45

Cx = AX + Bx

= 37.59 + 48.21

= 85.8

Cy = Ay + By

= -13.65 + 57.45

= 43.77

The magnitude is solved by

|c| = \sqrt{Cx^{2}+Cy^{2}  }

= √85.8² + 43.77²

= 96.32m

The magnitude of the vector c is 96.32m

Read more on the magnitude of a vector here:

brainly.com/question/3184914

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6 0
2 years ago
Dry cells become soft even when not in use. Explain.
mamaluj [8]
This is possible due to self-discharge. Very small internal currents inevitably occur in these cells over time and they will eventually exhaust the chemistry.
4 0
3 years ago
Explain the following observations:
Deffense [45]

Answer and Explanation:

a. An oxygen-filled balloon is not able to float in the air, because the oxygen inside the balloon is of the same density, that is, the same "weight" as the oxygen outside the balloon and present in the atmosphere. The balloon can only float if the gas inside it is less dense than atmospheric oxygen. Helium gas is less dense than atmospheric gas, so if a balloon is filled with helium gas, that balloon will be able to float because of the difference in density.

b. The ship is able to float in the water because its steel construction is hollow and full of air. This makes the average density of this ship less than the density of water, which makes the ship lighter than water and for this reason, this ship is able to float. In addition, the ship is partially immersed, allowing the weight of the ship on the water to counteract the buoyant force that the water promotes on the ship. Weight and buoyant are two opposing forces that keep the ship afloat.

6 0
3 years ago
A block with a mass M = 4.85 kg is resting on a slide that has a curved surface. There is no friction. The speed of the block af
natali 33 [55]

Answer:

The correct option is a

Explanation:

From the question we are told that

   The mass of the block is  m =  4.84 \ kg

    The height of the vertical  drop is h =  19.6 \  m

Generally from the law of energy conservation , the potential energy at the top  of the slide is equal to the kinetic energy at the point after sliding this can be mathematically represented as

        PE  =  KE

i.e     m *  g  *   h   =  \frac{1}{2} *  m *  v^2

=>    gh  =  0.5 v^2

=>   v = \sqrt{\frac{9.8 *  19.6}{0.5 } }

=>    v = 19.6 \  m/s

4 0
3 years ago
Please select the word from the list that best fits the definition Fossils up to 75,000 years old can be dated with ______.
mash [69]

Hello Paige,

Question - Please select the word from the list that best fits the definition Fossils up to 75,000 years old can be dated with ______.

Answer - Carbon 14

5 0
3 years ago
Read 2 more answers
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