<span>The atoms are grouped thus forming molecules. Each type of molecule is the combination of a certain number of atoms linked between them and in a specific way, whenever a molecule can contain atoms of different elements or of the same. And that in turn, Each atom retains its structural characteristics, beyond that they are part of different molecules because during the chemical reactions the atoms cannot be created or destroyed, but they are organized in a different way creating links between an atom and another.</span>
Answer:
The velocity
of the cart with respect to the ground is

if we consider North the positive y-direction and East the positive x-direction.
Explanation:
We have for relative motion the following expression:

Where
is the velocity of the cart with respect to the ground,
is the velocity of the cart with respect to the plane and
is the velocity of the plane with respect to the ground.
We find that:


Thus:
The centripetal acceleration of an object is given by the relation,

where Ac = centripetal acceleration =
R = radius of rotation = 15 m
V = speed of astronaut
Hence, 
solving this we get, V = 38.34 m/s
Answer: the top one
Explanation: hope this helps