13. A 10 kilogram rock is dropped off the top of a 20 meter tall building. What is the kineticenergy of the rock right before it impacts the ground?

The answer is c hope this

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.

Despite their crazy structure, human bones are surprisingly good!