

A sphere A of mass \(m\) is thrown at 50 m/s along \(\tan^{-1}(3/4)\). At the topmost point of its trajectory, it collides centrally with sphere B (mass \(3m\)) at rest. Gravity \(g = 10\,\text{m/s}^2\). Coefficient of restitution e = 0.3. Find the speed (m/s) of sphere A immediately after collision (round to 1 decimal).
If A + B means A is the mother of B; A - B means A is the brother of B; A % B means A is the father of B, and A \(\times\) B means A is the sister of B, which of the following shows that P is the maternal uncle of Q?