Calculating Wave Speed in a Stretched Brass Wire

[asz304]

Homework Statement

What is the wave speed in a brass wire with a radius of 3.35×10-4 m stretched with a tension of 120 N? The density of brass is 8.60×103 kg/m^3.

Homework Equations

v = sqrt( T/ mu )

The Attempt at a Solution

I have no clue about this problem. It gives me regular density but i need linear density in order for the formula to work and i don't know how or if i even can convert reg density to linear. Nor can i find any other relevant equations that would clear it up for me.

Thanks

 

[tiny-tim]

hi asz304!

It gives me regular density but i need linear density in order for the formula to work and i don't know how or if i even can convert reg density to linear.

easy-peasy …

linear density = mass per metre,

sooo … find the mass of a metre! ​

 

[asz304]

So the mass is just 8,600 kg?

And what will the length be? the radius?

Thanks

 

[tiny-tim]

nooo

what does a metre of this particular wire look like?

 

[asz304]

I got it!

Since you said mass of a meter, I used the cylinder formula

V= pi*r^2*h

the height is 1 m, which gives me volume. Then I used density*volume = mass, and I get 0.0154 kg to use in v = sqrt( T*L/m ).

Thanks!