Skaters with masses $80\,\text{kg}$ and $40\,\text{kg}$ travel straight towards one another and then collide. Before the collision, the heavier skater is travelling to the right with a speed of $2.0\,\text{m s}^{-1}$, while the lighter skater is travelling to the left with a speed of $1.0\,\text{m s}^{-1}$. Following the collision, the heavier skater travels to the right with a speed of $0.80\,\text{m s}^{-1}$. What is the relative speed of separation of the two skaters?
- A$0.6\,\text{m s}^{-1}$
- B$1.4\,\text{m s}^{-1}$
- C$2.2\,\text{m s}^{-1}$
- D$2.6\,\text{m s}^{-1}$