Using this block, a student wants to test a hypothesis that frictional forces are independent of the area of contact between the block and the surface it slides on. Which method is BEST to collect the data needed? D- Pulling the block across the same surface 10 times, adding a weight on top of the block each time.
A- Pulling the block across 10 different surfaces with the largest side in contact with them.
B- Pulling the block across the same surface with a different side in contact each time.
C- Pulling the block across three different surfaces with a different side in contact with each surface

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490 n  f=125n a=2.5m/s2

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.