Question

A Slinky has a k-value of 0.80 kg/s2.  If it is stretched to 2.7 meters, what is its elastic potential energy?

Answer 1

$$PE_{elastic}=\dfrac{1}{2}kx^2,$$ $$PE_{elastic}=\dfrac{1}{2}\cdot 0.8\ \dfrac{kg}{s^2}\cdot(2.7\ m)^2=2.92\ J.$$