A 0.40 kg object is moving on a frictionless surface with a speed of 30 m/s. A force of 2.0 N is
applied continually until the velocity of the object
has been reversed. How long was the force
applied?

Iwas going to ask that quesytion  sorry dude i dont  know : (    : /

Ithink it is letter b, i may be wrong but i think that is the answer

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.