What questions in particle physics led to the necessity for the development of the quark theory? what were the deficiencies in the older theories that made it necessary to formulate a theory of particle structure on a level below (i. e., smaller than) that of electrons, protons, and neutrons? what observational evidence is there for the existence of smaller particles within the proton, for example?

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.