Answer:
Explanation:
Given
Spring force constant [tex]k=5\ N/m[/tex]
Relaxed length [tex]l_0=2.59\ m[/tex]
mass is attached to the end of spring and allowed to come at rest with relaxed length [tex]l_2=3.86\ m[/tex]
Potential energy stored in the spring
[tex]U=\frac{1}{2}k(\Delta x)^2[/tex]
[tex]\Delta x=l_2-l_0[/tex]
[tex]U=\frac{1}{2}\times 5\times (3.86-2.59)^2[/tex]
[tex]U=4.03\ J[/tex]