Adeep-sea diver should breath a gas mixture that has rthe same oxygen partial pressure as at sea level, where dry air contains 20.9% oxygen and has a total pressure of 1.01x105 n/m2.
when developing a strategy for solving this problem, how can the given information and the principles that govern this context lead me to what the problem is asking for?

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. 

So are u adding some additional catalyst