Last night I spent my time dropping ice cubes from the top of the bleachers onto students belon. If an ice cube was dropped from the top of the bleachers (approximately 20 meters high) and the student caught the ice cube 2 meters before it hit the ground, 1- how much time did he have to react?
2- how fast was the Ice Cube moving when the student caught it (ignoring air resistance)?
need ASAP please​

One splits the atoms and molecules  the other combines them

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.