I'm not 100% sure, but I believe what you mean is when they eject the old propulsion motors. Yes, they land in the ocean and the US Navy retrieves them for later use.
a) The x-coordinate of the center of gravity is
.
b) The y-coordinate of the center of gravity is
.
<h3>Determination of the coordinates of the center of gravity</h3>
Let suppose that each square has an <em>uniform</em> density, the coordinates of the center of gravity of each square with respect to the origin are, respectively:



The center of gravity of the <em>entire</em> system is found by applying definition of <em>weighted</em> averages:
Where
,
,
and
are weights of the each square, in newtons.
Now we proceed the coordinates of the center of gravity of the entire system:



a) The x-coordinate of the center of gravity is
. 
b) The y-coordinate of the center of gravity is
. 
To learn more on center of gravity, we kindly invite to check this verified question: brainly.com/question/20662119
Answer:
d
Explanation:
because when things go forward quickly things get pushed back
The first person is Neil Armstrong
Answer:
Force, 
Explanation:
Given that,
A potential energy function for a system in which a two-dimensional force acts is of the form of :

We need to find the force that acts at the point (x, y). The force in 2 dimensional with components is given by :

So, the force acting at the point (x,y) is
. Hence, this is the required solution.