A rock is thrown upward with a velocity of 15 m/s from the top of a 34 m high cliff and he misses the cliff on the way back down will the rock be 4 Meters from the ground level?

This is the answer: body 1 + engine 2

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. 

Answer (d) the universe had cooled enough for atoms to combine, protons and neutrons were too far apart to form nuclei;