A spaceship fires a movement thruster, releasing gases at high pressure.

What are the forces in the force pair for this example?

the force the gases apply to the ship
the force the ship applies to space
the force the gases apply to the ship
the force the ship applies to the gases
the force the gases apply to space
the force the ship applies to the gases
the force the gases apply to space
the force the ship applies to the gases

The magnets would be | n s | and | s n|

The relationship of both of them

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero.