Please fill in the blank if you don't mind.

Energy is the ability to do work which measures what

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?