Question:
Revisit Example 3-7, and assume that the body with the slingshot is below the boy in the tree (Fig. 3-40) and so aims upward, directly at the boy in the tree. Show that again the boy in the tree makes the wrong move by letting go at the moment the water balloon is shot.
Figure 3-40.
Source: Giancoli, Douglas C., Physics: Principles with Applications, 7th Edition, 2014.
Quick Answer:
see video
Giancoli 7th Edition, Chapter 3, Problem 36
(5:25)