Answer:
The linear mass density is of the string
![\mu= 5.51*10^(-3) kg / m](https://img.qammunity.org/2021/formulas/physics/college/ybyfhb8491136ghd010vbzpz7h9laz6je7.png)
Step-by-step explanation:
From the question we are told that
The distance between wall and pulley is
![d = 0.405m](https://img.qammunity.org/2021/formulas/physics/college/mqjyjdqia8a8pd7kto40a9hd9f285fr14s.png)
The mass on the hook is
![m = 25.4\ kg](https://img.qammunity.org/2021/formulas/physics/college/u8ilkzwzv69l1fsvo6i2qomyqehiim73on.png)
The frequency of oscillation is
![f = 261.6 Hz](https://img.qammunity.org/2021/formulas/physics/college/x6rayjfbf2ve25b6kxe1c9papovbbxp6y7.png)
Generally, the frequency of oscillation is mathematically represented as
![f = (1)/(2d) \sqrt{(T)/(\mu) }](https://img.qammunity.org/2021/formulas/physics/college/nbqfilgxkryzoz324zeq6e7wovgo3u2drx.png)
Where T is the tension mathematically represented as
T = mg
Substituting values
![T = 25.4 *9.8](https://img.qammunity.org/2021/formulas/physics/college/iiimakkdlwvnu7o0xa9yzckn6ee4y4s3p6.png)
![=248.92N](https://img.qammunity.org/2021/formulas/physics/college/urrf3lj9hf5s9h38416atjj7qkwellr1w7.png)
is the mass linear density
Making
the subject of the formula above
![\mu = (T)/((2df)^2)](https://img.qammunity.org/2021/formulas/physics/college/seg23d0q5axpy59tve4pr835xt5579k7gk.png)
Substituting values
![\mu = (248.92)/((2 * 0.405 * 261.6)^2)](https://img.qammunity.org/2021/formulas/physics/college/l9310p3t07wqxtxg3ugk0tmdki234i38vu.png)
![\mu= 5.51*10^(-3) kg / m](https://img.qammunity.org/2021/formulas/physics/college/ybyfhb8491136ghd010vbzpz7h9laz6je7.png)