The energy of a spring in motion is quantified as kinetic energy. ### SI Unit ### Unit Analysis for Kinetic Energy ($K$) $K = \frac{1}{2}\ mv^{2}$ $K = kg\frac{m}{s^{2}} \cdot m$ $K = kg\frac{m}{s^{2}} \cdot m$ $K = N \cdot m$ $K = joule$