As two magnets are pulled away from each other, what will happen to the strength of the force between them? A The force between them will increase
B The force between them will stay the same.
C The force between them is not affected by the distance between them.
D The force between them will decrease.

Kiloleter, mega leterhope this !

The answer is frictional force

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. 

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.