David is driving at a steady speed (v) when he spots Tina 1000 m ahead of him. At that moment she accelerating at a steady rate (a) from rest, and moves towards him. At what instant will they reach the same position

This did i unseated, sorry

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.