Consider a pemfc operating at 0.8 a/cm2 and 70∘c. hydrogen gas at 90∘c and 80% relative humidity is provided to the fuel cell at the rate of 8 a. the fuel cell area is 8 cm2 and the drag ratio of water molecules to hydrogen, α, is 0.8. find the water activity of the hydrogen exhaust. assume that p = 1atm and that the hydrogen exhaust exits at the fuel cell temperature, 70∘c.

Sorry i don’t know what to do

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. 

Need more information like a picture