chikis wrote:Okay, for whoever wants to see my working:
Velocity, v of the spring = 300ms-1. Number of vibration is the same as the frequency, f which we are to find. The lengt of the string is the same as the wavelenght w = 50cm = (50/100)m = 0.5m,
using v = f(w)
f = v/w
f = 300/0.5
but the answer I got is not the same with the one at the answer page of my book. I brought the problem in so that you guys can analyse it and tell whether am right or wrong. If am right, congratulate me and if am wrong, lead me and resolve the problem, then tell me where am wrong and correct me. Thank you.
chikis wrote:When the string is plucked at it centre it will vibrate. The number of that vibration is equal to the frequency.
Am a secondary school leaver warming up for higher education.
I have heard about node and antinode, is just that I don't have a full knowledge about what is all about.
chikis wrote:I think I have gotten the clue now. The lenght of the string, L = wavelenght,W/2
thus W = 2L
velocity, V = Frequency, F * W
using the relation with what I have:
F = V/ W
I hope am now on the right track?
neuro wrote:I do agree with you that we have only one standard unit for linear velocity.
Still, I would appreciate your not being so rude, and trying instead to understand what I am asking.
The string vibrates.
Every point travels in space.
The speed of such travel changes at avery moment (and is maximum for the center point, zero at the limiting fixed points)
In particular, the speed sinusoidally varies with time, between a maximum speed in one direction (when crossing the middle point of the oscillation) and a maximum speed in the other direction (again when crossing the middle point).
This is velocity, linear velocity, meters/s, but it is an ACTUAL displacement velocity along the TRASVERSE axis of the string.
Then you can look at the string as if it where the representation of a wave that propagates.
Such a wave would have a wavelength twice the length of the string, because at each moment the string only "represents" half a wave.
Such a wave would also have an oscillation frequency (cycles/s = Hertz).
You can ABSTRACTLY think of a LINEAR VELOCITY of the wave, as given by the length travelled in one cycle (wavelength) multiplied by the number of cycles in a second (frequency).
NOTICE THAT THIS IS A LINEAR VELOCITY ALONG THE STRING (not transversally).
NOTHING MOVES LONGITUDINALLY AT THAT SPEED IN YOUR SYSTEM!!
Still, this is the way you seem to interpret speed:
I am not saying speed is something different from m/s, I am only asking whether in such a system it is standard convention to talk about velocity to mean the abstract linear speed of the wave ALONG the string, rather than the ACTUAL speed of the string (of the center-point of the string, not of the wave) TRANSVERSALLY with respect to the axis of the string.
Actually, I am not asking you this, but the engineers and physicists here
chikis wrote:My heart is still runing round looking for commendation. I want somebody to approve or disapprove my last working as regards to the problem I used in starting this thread. By simply writing yes if approved and no if not. Or just by making statemement showing your approval or disapproval.
chikis wrote:How can I show my work with skech when the question does not require that. Perhaps if am to represent my work with skech and send it in, I don't have a means to do that becuase I don't have a scanner. Where did I not use complete and consistent units? The number of vibration made by the string in one second is 300Hz. So where am wrong specifically? Qoute it out let me see.
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