Answer:
Intensity
Explanation:
The intensity of a sound wave is equal to the ratio between to the power emitted by the source divided by the area of the spherical surface through which the wave propagates:

where
P is the power
is the area of the spherical surface
r is the distance from the source
As we see from the formula, the intensity is inversely proportional to the square of the distance from the source:

so, intensity is the correct answer.
At the tip of either of the magnets poles
Represent the motion in the number line.
Movement to the east is movement to the negative side. Movement to the west is movement to the positive side.
Total displacement = -680m + 430m - 620m = -870m
Total displacement = 860m to the east.