5.

A rock is initially at rest with respect to a planet and located very far away, such Rock that gravitational potential energy is negligible with respect to planet center. V1 The rock is released and accelerates toward the planet. An observation tower is built three planet radii high to observe the rock as it falls to to planet. When the rock passes the top of the tower, its speed is V 1. 3R Neglecting air resistance, what is the rock's speed when it hits Tower planet's's surface as a function of v, only? R = Planet's's Radius R Planet