When looking into a tall glass of tea, you observe the tea looks darker when looking from top to bottom than when looking from the side of the glass through to the other side (assume the glass is colorless, no ice cubes). your observation is best explained by: a. differences in concentration of the tea
b. differences in pathlength
c. the effect of gravity
d. none

The correct answer is b. Differences in Path Lenght

Explanation:

In this area of knowledge, there two main ways of referring to Path Lenght:

1. The total distance an object travels from a starting point, without considering trajectory.

2.  When talking about wavelength, because this relates to light and how it travels throughout different mediums. This concept is used in calculating constructive and destructive interference of waves, and is responsible for seeing different shades of tea color.

Hope this helps!