A body of mass $m$ moving at speed $v$ collides head-on with a second body of mass $m$ moving in the opposite direction at speed $v$. After the impact, the two bodies remain joined together. Determine the total loss of kinetic energy in this collision.
- A$0$
- B$\frac{1}{2}mv^2$
- C$mv^2$
- D$2mv^2$