What Is the Speed of Waves on a Guitar String?

[toothpaste666]

Homework Statement

A 65-cm guitar string is fixed at both ends. In the frequency range between 1.0 and 2.0 kHz, the string is found to resonate only at frequencies 1.2, 1.5, and
1.8kHz .

What is the speed of traveling waves on this string?

Homework Equations

f = v/2l

The Attempt at a Solution

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Each one of these is a multiple of .3 so i think that is the fundamental frequency. Then I use f=v/2l or
v=2lf
v= 2 * .65 * .3
v = .39

but i did it wrong. can someone help please

 

[jz92wjaz]

Check your units. You need to convert kHz to Hz in order to come up with a velocity in m/s.

 

[voko]

Homework Equations

f = v/2l

What does "l" mean in that equation? And where does the equation come from?

 

[toothpaste666]

Check your units. You need to convert kHz to Hz in order to come up with a velocity in m/s.

oh wow can't believe i missed that. thank you