Which methods could you use to calculate the y-coordinate of the midpoint of a vertical line segment with endpoints at (0, 0) and (0, 15)?

One of the most convenient ways of finding or calculating for the midpoint of the line segment is to get the average of the coordinates of the points.

Average of abscissa = (0 + 0) / 2 = 0

Average of ordinate = (0 + 15) / 2 = 7.5

 Hence, the midpoint of the line segment is equal to (0, 15/2).

The value of the y-intercept is 15/2. 

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na

The answer is d- principle of faunal succession.