Calculate the density of the material for a vibrating string

[Bolter]

Homework Statement

See image attached below

Relevant Equations

Frequency = 1/2L * sqrt(T/u)

Here is the question that is is given to me

Part a:

Part b:

I have given this a go and was wondering if my answer seems reasonable.

I had worked out that the mass per unit length (mu) is also the density * cross sectional area of wire

Thanks!

 

[kuruman]

It looks reasonable.