what happens to the electric force if the magnitude of both charges in an electrostatic interaction is tripled

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

  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.

b. a lightning bug, plug of grass, and a worm