Question

A launching mechanism consists of an arm (uniform rod with mass 250. g and length 75.0 cm) with a holder (negligible mass) at one end mounted to a hub of radius 3.00 cm and negligible mass at the other end. A string is wrapped around the hub and passes to a spring of constant k = 2550 N/m that is unstretched when the launcher is in the vertical position. The launcher arm is pulled into the horizontal position and loaded with a 50.0 g point mass. It is released from rest and stops by hitting a pin at the vertical position. The projectile leaves the launcher with an initial horizontal velocity at a height of 2.00 m above the ground. Where does it land?