The answer is letter A. meteorite bombardment.
During the Earth's earliest beginning, it went through a period of catastrophic and intense formation. By 3-8- 4.1 billion years ago, Earth's atmosphere was never the same as today. This is because of its formation during the pre-Cambrian period whereby t<span>he Earth formed under so much heat and pressure that it formed as a
molten planet.
</span>
Earth was bombarded continuously by the remnants
of the dust and debris — like asteroids, meteors and comets — until it formed
into a solid sphere, pulled into orbit around the sun and began to cool down during the Hellish period (4.5 to 3.8 billion years ago).
<span> </span>.To know more of this topic, see attached file.
Answer:
Part a)

Part b)

Part C)

Part d)
Due to large magnitude of friction between road and the car the momentum conservation may not be valid here as momentum conservation is valid only when external force on the system is zero.
Explanation:
Part a)
As we know that car A moves by distance 6.1 m after collision under the frictional force
so the deceleration due to friction is given as



now we will have




Part b)
Similarly for car B the distance of stop is given as 4.4 m
so we will have


Part C)
By momentum conservation we will have



Part d)
Due to large magnitude of friction between road and the car the momentum conservation may not be valid here as momentum conservation is valid only when external force on the system is zero.
Answer:

Explanation:
Given:
mass of first particle, 
mass of second particle, 
mass of third particle, 
coordinate position of first particle in meters, 
coordinate position of second particle in meters, 
coordinate position of third particle in meters, 
<u>Now, gravitational force on particle 3 due to particle 1:</u>



towards positive Y axis.
<u>gravitational force on particle 3 due to particle 2:</u>



towards positive X axis.
<u>Now the net force</u>



<em>For angle in counterclockwise direction from the +x-axis</em>

Atoms begin to gravitate together to form a center