Finding the length of a string given f, F, λ and m

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The discussion focuses on solving a physics problem involving the length of a string given specific parameters: frequency (f), force (F), wavelength (λ), and mass (m). The original formula used was f(λ)=sqrt[F/(m/L)], which led to an initial calculation of L that seemed questionable. After further exploration, the user discovered a simpler approach by calculating wave velocity (v) using the relationship v=λ*f, and then rearranging to find L as L=[(m)(V^2)]/F. This revised method appears to be more straightforward and aligns with the values provided in the problem. The conversation highlights the importance of verifying formulas and approaches in physics assignments.
romakarol
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Going through my physics assignment tonight, so that's 10 questions I'll be posting. Since I'm thoroughly hopeless at this subject most of my attempts will be based on my elite google-fu or trawling through lecture notes, bear with me and thanks!

1. Homework Statement
frequency (f)=160hz
Force (F)=150 Newtons
wavelength (λ)=0.40m
mass(m)=6 grams

find the length of a string with these properties

Homework Equations


f(λ)=sqrt [F/(m/L)]

found this formula and the statement "solve for L" for this exact question online.
I put the values in above, I believe I interpreted them right.

The Attempt at a Solution


It seemed a bit dodge to re-arrange, but i got L on it's own to be:
L= [F/(fλ ^2)]/m
(with values)
[150/(160x0.40)^2]/6=0.0061m...I have a feeling I may be off here XD.
 
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romakarol said:
f(λ)=sqrt [F/(m/L)]
What is that equation? The right hand side (RHS) looks like the velocity of waves on a string...
 
I'm not sure, someone asked the same question as me on some website and that formula along with "solve for L" was the one-sentence reply. I used it because it seems to involve all the values listed in the question and can be used to find L. Is it incorrect?
 
Edit: see new post
 
Wait I found a simpler formula based on what you said:

upload_2016-4-8_2-10-7.png


I can get v since the wavelength and frequency is given (wavelength=v/frequency).

So if I re-arrange it to get L on its own, then L=[(m)(V^2)]/F, correct?
 
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