How does panting help the dog maintain homeostasis?

Panting helps the dog maintain homeostasis because panting is the equivalent of humans sweating. Dogs pant to cool themselves down to reachieve their "normal" body temperature. Homestasis is the individuals sense of equilibrium and a dog panting helps them to acheive their temperature homeostasis.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.