Answer: The potential energy is 4.68 J
Step-by-step explanation:
The force done by an spring is equal to:
F= K*x
where K is th force constant of the spring, and x is the change in the distance with respect to the relaxed lenght.
We know that the relaxed lenght is 2.47m and the force constant is 5.5N/m
Now, we know that after hanging a mass in the spring, the new lenght is 3.78m
So the displacement will be equal to: 3.78m - 2.47m = 1.31m
Now, the potential energy stored by a spring can be calculated as:
PE = (1/2)*k*x^2 = (5.5N/m*(1.31m)^2)/2 = 4.68 J