Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity.
<span>d. 93 billion miles
</span>Earth, being the third planet from the sun is unique in the universe because it is currently the only planet known to support life. Earth's distance from the sun is really one of the key reasons why it is has widespread life.Earth occupies what scientists sometimes call the Goldilocks zone. Its distance from the sun means its neither too hot nor too cold to support liquid water. Water is thought to be a key ingredient for life.<span> The energy from the sun in just the right intensity and the availability of water on the earth make it possible for life to thrive on earth. Plants use both these resources for photosynthesis and make nutrients that are available to support the life of animals on the earth. </span>
To develop this problem it is necessary to apply the concepts related to Gravitational Potential Energy.
Gravitational potential energy can be defined as
As M=m, then
Where,
m = Mass
G =Gravitational Universal Constant
R = Distance /Radius
PART A) As half its initial value is u'=2u, then
Therefore replacing we have that,
Re-arrange to find v,
Therefore the velocity when the separation has decreased to one-half its initial value is 816m/s
PART B) With a final separation distance of 2r, we have that
Therefore
Therefore the velocity when they are about to collide is 
Answer:
157.9 kg
Explanation:
Density: This can be defined as the ratio of the mass of a body and it's volume.
The S.I unit of density is kg/m³.
From the question,
Density = Mass/volume
D = m/v............................ Equation 1
Where D = Density of gold, m = mass of gold, v = volume of gold.
make m the subject of the equation
m = Dv.................... Equation 2
Since the gold is a cube,
v = l³................... Equation 3
Where l = length of the gold cube.
Substitute equation 3 into equation 2
m = Dl³............... Equation 4
Given: D = 19300 kg/m³, l = 0.2015 m
Substitute into equation 4
m = 19300(0.2015)³
m = 157.9 kg.
