Answer:
[tex]\gamma=6.07*10^5\frac{N}{m^2}[/tex]
Explanation:
For a linear elastic material Young's modulus is a constant that is given by:
[tex]\gamma=\frac{F/A}{\Delta L/L_0}[/tex]
Here, F is the force exerted on an object under tensio, A is the area of the cross-section perpendicular to the applied force, [tex]\Delta L[/tex] is the amount by which the length of the object changes and [tex]L_0[/tex] is the original length of the object. In this case the force is the weight of the mass:
[tex]F=mg\\F=55kg(9.8\frac{m}{s^2})\\F=539N[/tex]
Replacing the given values in Young's modulus formula:
[tex]\gamma=\frac{F/\pi r^2}{(L_1-L_0)/L_0}\\\gamma=\frac{539N/\pi(0.045m)^2}{(5.31m-4.66m)/4.66m}\\\gamma=6.07*10^5\frac{N}{m^2}[/tex]