A girl is playing on a playground. Her mother, 100 m away from her, calls her with a sound power of P = 1 107 W. Assume sound is emitted radially all around the mother. (a) Calculate the intensity level of the sound at the girl's location. (b) Can the girl hear her? Justify your answer. (c) How close does the mother need to be for the child to hear her? Constant to consider: Threshold of hearing: I0 = 1 1012 W/m2