You are a knight storming a castle but they don't want to let you in. Luckily you brought your trusty 15.0-m long, 22-kg uniform ladder!! You place it against a smooth vertical wall with the bottom of the ladder 3.0 m from the wall. There is a lot of slippery mud so naturally you are worried about the latter slipping. The coefficient of static friction between the floor and the ladder is 0.28. What distance, measured along the ladder from the bottom, can a 60-kg person climb before the ladder starts to slip