A uniform thin bar AB of length L = 4 ft is released from rest at an angle θ = θ1. As the...

A uniform thin bar AB of length L = 4 ft is released from rest at an angle θ = θ1. As the bar slides, the ends A and B maintain contact with the surfaces on which they slide. Neglecting friction and knowing that the end A has a speed of 18 ft/s right before hitting the floor, determine θ1.

Figure P8.18