What is the ultimate source of energy that makes the sun shine?

The sun's energy comes from thermonuclear fusion reactions.

Explanation:

Due to the Sun's strong gravitational pull, hydrogen atoms fuse, resulting in helium atoms. During this process, tremendous amounts of energy are released, or the energy of the Sun.

  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.