Objects 1 and 2 attract each other with a electrostatic force
of 72.0 units. If the charge of Object 1 is halved AND the
charge of object 2 is tripled, then the new electrostatic force
will be units.

the amount of current in the coil

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.