Review conceptual example 2 as background for this problem. a charged particle moves through a velocity selector at a constant speed in a straight line. the electric field of the velocity selector is 5400 n/c, while the magnetic field is 0.344 t. when the electric field is turned off, the charged particle travels on a circular path whose radius is 5.88 cm. find the charge-to-mass ratio of the particle.

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. 

Answerreduces the visual acuity or sharpness