Birth Star:
Main sequence stars fuse hydrogen atoms to form helium atoms in their cores. About 90 percent of the stars in the universe, including the sun, are main sequence stars. These stars can range from about a tenth of the mass of the sun to up to 200 times as massive. Stars start their lives as clouds of dust and gas.
Death Star:
Dense regions in the clouds collapse and form "protostars". Initially, the gravitational energy of the collapsing star is the source of its energy. Once the star contracts enough that its central core can burn hydrogen to helium, it becomes a "main sequence" star.
Its A according to Ed Genuity
Answer:
30.63 m
Explanation:
Using y = ut + 1/2gt² where u = initial speed of block = 0 m/s, g = acceleration due to gravity = 9.8 m/s² and t = time of fall = 2.5 s and y = height of fall.
So, substituting the values of the variables into the equation, we have
y = ut + 1/2gt²
y = 0 m/s × 2.5 s + 1/2 × 9.8 m/s² × (2.5 s)²
y = 0 m + 4.9 m/s² × 6.25 s²
y = 0 m + 30.625 m
y = 30.625 m
y ≅ 30.63 m
So, the brick fell 30.63 m
gravitational Potential energy is given by

here we have
m = 200 kg
h = 21000 m
now we will have


so GPE of balloon will be 41160000 J above the given height from ground