Light travels at a speed of 3.0 ´ 108 m/s. if it takes light from the sun 5.0 ´ 102 s to reach earth, what is the distance between earth and the sun?

The velocity is distance over time.
v = d/t
The requirement here is to get the distance.
d = v*t
d = (3 × 10^8) * 500 = 1.5 × 10^11 meters

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.