The wavelength of the note is

. Since the speed of the wave is the speed of sound,

, the frequency of the note is

Then, we know that the frequency of a vibrating string is related to the tension T of the string and its length L by

where

is the linear mass density of our string.
Using the value of the tension, T=160 N, and the frequency we just found, we can calculate the length of the string, L:
Well, the density of the water is

so i believe that is what the question is asking for :)
Answer:
v_average = (d₂-d₁) / Δt
this average velocity is not necessarily the velocity of the extreme points,
Explanation:
To resolve the debate, it must be shown that the two have part of the reason, the space or distance between the two points divided by time is the average speed between the points.
v_average = (d₂-d₁) / Δt
this average velocity is not necessarily the velocity of the extreme points, in the only case that it is so is when there is no acceleration.
Therefore neither of them is right.
Answer: Pedaling your bike : acceleration :: applying the brakes : inertia.
The reason I think this to be the answer to the analogy is because there is energy and work used in both processes (and the unit focuses on forces); gravity is constant and does not change whether one pedals or applies brakes. And I do not think it's deceleration, as deceleration tends to equate to acceleration within the physics perspective.
Edit: I should also add that since you clarified that your unit is motion and forces, Newtons 1st law is the law of inertia. The way to change an objects motion for it to slow down is by applying an additional force. That resistance the bike experiences to slow is the process of inertia. Inertia happens in order to accelerate an object (either by slowing it down, or speeding it up): i.e., the resistance to change.