Zebras are classified as vertebrates because they have two germ layers. bilateral symmetry. a backbone. a brain.

does anyone know or what?

the closer the planet is to the sun, the larger the gravity

  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.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.