Yes indeed, that is a true statement. Truer words are seldom written, and I could not agree with you more.
In case you are asking a question, I can kind of see how this might be a question if there is a blank after "... the change in ..." that is to be filled with one or more new words.
If that is the situation, then the blank can be filled with "frequency or wavelength" .
Answer:
Please refer to the figure.
q1 is a negative charge, and q2 and q3 are positive charges. So, the force exerted by q1 on q3 is attractive, and the force exerted by q2 on q3 is repulsive, which means F13 is directed towards left, and F23 is also directed towards left.


The net force on q3 is the sum of these two forces:

Since both forces are directed towards left, their sign should be negative.
Answer:
The principal hair fiber used to produce textile fabrics is sheep's wool. In wild sheep, the wool is a short, soft underlayer protected by longer, coarser hair. ... Fur fibers from animals such as mink and beavers are sometimes blended with other hairs to spin luxury yarns but are most often found as fur pelts.