A golf ball is launched with the initial conditions shown in the figure. Determine the radius of curvature of the trajectory and the time rate of change of the speed of the ball (a) just after launch and (b) at apex. Neglect aerodynamic drag. Assume v = 157 mi/hr, θ = 12∘ Answers: (a) ρ = ft, v˙ = ft/sec (b) ρ = ft, v˙ = ft/sec
![A 50 kg child stands on the edge of a stationary thin rod of length 5.0 m and mass M = 100 kg, free to rotate around its center of mass O. The child catches a ball of mass 2.0 kg thrown by a friend. Just before the ball is caught, the ball has a horizontal velocity of magnitude 30 ms−1, at angle θ = π/4 with a rod, as shown in Fig. 4 (a) What is the angular speed of the thin rod just after the ball is caught? (b) What is the mechanical energy of the child after the ball has been caught? [6 marks] (c) With what horizontal velocity, at an angle ϕ = π/6 with respect to the rod, has the boy to throw away the ball such that after the launch he will stay at rest? [7 marks]](https://www.doubtrix.com/uploads/editor/9895436237ysrDMhQJnq.png)
