Answer:
Calculating Center
Shapley correctly determined the galactic center of the Milky Way to be located in the constellation of Sagittarius. He did this by mapping out a three-dimensional distribution of the globular clusters.
Explanation:
Mark me the Brainliest..PLS
Answer:
4000m/s
Explanation:
It would be this because sound travels faster through a solid rather than a liquid.
Answer:

Explanation:
given,
s = 400- 16 t²
we know,
Velocity of an object is defined as the change in displacement per unit change in time.
velocity an also be return as




Hence, instantaneous velocity function given by 
To calculate instantaneous velocity, you need to insert value of time.
ex, instantaneous velocity at t = 4 s
v = -32 x 4 = -128 m/s.
Sorry, I don't know but I think the correct answer is the first option.