A ball is projected vertically upward from an initial position \(5.0 \mathrm{~m}\) above the ground (Figure P3.71). At the same instant, a cube is released from rest down an ice-covered incline, from a height not necessarily equal to \(5.0 \mathrm{~m}\). The two objects reach the ground at the same instant, and both have a final speed of \(15 \mathrm{~m} / \mathrm{s}\). What is the angle of the incline?

Data from Figure P3.71

5.0 m