Model a parabolic GRIN fiber by the equivalent multiple-step approximation.
Let n1=1.5, Δ=0.01. Divide the radius into 10 equal parts. Consider a ray crossing the fiber axis at 5° with respect to that axis (and inside the fiber). Sketch its progress through the fiber until it turns back and re-crosses the fiber axis. (The angles can be magnified on your sketch.)
At what value of r/a did the ray turn back by total reflection?

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. 

Hi.the measurement  amperes represents the rate at which current flows.it's like the measurement of water flowing through a pipe.~