The object's speed will not change.
In fact, after the astronaut throws the object, no additional forces will act on it (since the object is in free space). According to Newton's second law:

where the first term is the resultant of the forces acting on the body, m is the mass of the object and a its acceleration, we see that if no forces act on the object, then the acceleration is zero. Therefore, the acceleration of the object is zero, and its velocity remains constant.
Answer:
The answer is A/B, they're the same answer anyways.
Explanation:
Chromatic aberration is the result when the lens fail to focus all the colors on the same point. The light then focuses in different points,and could lead to causing two images at once. The main culprit of this is usually dispersion.
To solve this problem it is necessary to apply the concepts related to the geometry of a cylindrical tank and its respective definition.
The volume of a tank is given by

Where
d = Diameter
h = Height
Considering that there are two stages, let's define the initial and final volume as,


We know as well by definition that

Then we have for the statement that


Replacing the previous data


Solving to get h,

Therefore the change is



Therefore te change in the height of the water in the tank is 0.37mm
The movement of a fluid during convection is a circular/oval motion since the fluid at the top sinks and the fluid at the bottom rises.
Hope this helps :)