Two people relaxing on a deck listen to a songbird sing. one person, only 1.66 m from the bird, hears the sound with an intensity of 6.86×10−6 w/m2.
a bird-watcher is hoping to add the white-throated sparrow to her "life list" of species. how far could she be from the bird described in example 14-8 and still be able to hear it? assume no reflections or absorption of the sparrow's sound.
express your answer using three significant figures.

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.