1. A uniform beam 16.0 feet long and weighing 300 pounds is placed such that it protrudes 4.0 feet over the edge of a flat roof. How far out from the edge of the roof can a 150-pound man walk on the beam without tipping the beam?
2. A uniform ladder 10.0 feet long and weighing 30 pounds is placed against a perfectly smooth wall, its lower end being 6.0 feet from the wall. What is the least coefficient of static friction between the lower end of the ladder and the floor that will permit a 160-pound man to.