Answer:
Explanation:
We shall apply law of conservation of mechanical energy for projectile being thrown .
Total energy on the surface = total energy at height h required
a ) At height h , velocity = .351 x ( 2 GM/R x h )



h = .14 R
b )


h = .54 R
c ) least initial mechanical energy required at launch if the projectile is to escape Earth
= GMm / R + 1/2 m (2GM/R)
= 0
When conducting a search to identify a text's credibility and reliability, you have to check the following characteristics:
- Sources: where the information is obtained and it is supposed to be true. It is said that you need at least three different sources that explain the same information for it to be validated.
- Is the article is current?: articles could change all the time, specially scientific ones because new discoveries can change what was discovered before, so it is important to check if the text you are reading is current or not, and if it is not, you need to check if something has changed during all those years.
<h3>Article's credibility</h3>
In this exercise, you have to present an article and describe the purpose of the source and if the article is current or not.
For example, let's select an article called "How using social media affects teenagers".
The purpose of the sources in this article is to demonstrate how social media affects teenagers using different surveys.
Check more information about sources here brainly.com/question/24708478
Answer:
conserving water is important because it keeps water pure and clean while protecting the inviorment
To solve this problem it is necessary to apply the concepts related to gravitational force and centripetal force,
By definition the gravitational force on earth is defined under Newton's second law where,

Where,
m = mass
g = Gravity acceleration
At the same time we know that the Centripetal force is equivalent to

Where,
m = mass
v = Velocity
r = Radius
Since there is a balance between the two, you have to


Re-arrange to find the velocity we have,



Therefore the minimum speed must be 11.37m/s
I believe it is B because comets are smaller and meteoroids is smaller to. So I think it is B. Hope this helps!! #Batgirl