Photosynthesis in an endothermic reaction. Endothermic reactions are all those chemical reactions that in their transformation process, in 2 or more different substances, consume Caloric Energy, in which, the products obtained possess higher energy levels, than the initial reagents, since they have taken part of the heat of the environment.
That's hard. The action might be when you go to lift your feet off the ground and the reaction force is letting your feet touch the ground again while taking a stride. Hope this helps.
