Why did president franklin d. roosevelt establish social security?

On this day in 1935, President Franklin D. Roosevelt signs into law the Social Security Act. Press photographers snapped pictures as FDR, flanked by ranking members of Congress, signed into law the historic act, which guaranteed an income for the unemployed and retirees.

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. 

Ibelieve the answer is arteries