Two gliders are moving towards one another on a horizontal air track. Glider P has a mass of $0.30\,\text{kg}$ and is travelling at a constant speed of $1.2\,\text{m s}^{-1}$. Glider Q has a mass of $0.60\,\text{kg}$ and is travelling at a constant speed of $1.8\,\text{m s}^{-1}$. The gliders undergo a perfectly elastic collision. What are the speeds of the two gliders after the collision?
Physics 9702 · AS & A Level · Linear momentum and its conservation