# Wave speed in 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

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! So the mass is just 8,600 kg?

And what will the length be? the radius?

Thanks

nooo what does a metre of this particular wire look like?

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!