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 
Homogeneity and isotropy, On large enough scales, the Universe looks pretty much the same in all directions. The big bang theory is based on two assumptions: the first is centered around Einstein's general theory of relativity, which accurately describes gravity and the interactions of matter; and the second, also known as the cosmological principle, asserts that the universe is homogeneous and isotropic on a large enough scale.
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Please give Brainliest!
A textbook would hit the ground first
Factors:
-Textbook weighs most
-Pillow is flat and fluffy not very aerodynamic) also is very light
-Paper airplane will glide to the ground do to its wings and will hit the ground last
Its b i literally have had this exact question
1. Most PE, because PE is directly proportional to distance (height)
Height: 100 meters
Speed: 0 mph
2. Most KE, because KE is directly proportional to speed
Height: 10 meters
Speed: 40 mph
3. Most TE, average KE
Height: 10 meters
Speed: 40 mph
4. The skater gains thermal energy as she goes down the slope, because the speed of the skater increases, so it increases the total kinetic energy of the particles, and makes them vibrate faster, resulting in a higher temperature.
