A 69-kg person stands on a 6.0-m-long 54-kg ladder. The ladder is tilted 60∘ above the horizontal. The coefficient of friction between the floor and the ladder is 0.39. The coefficient of friction between the wall and the ladder is zero.

What distance d along the ladder can the person pass without the ladder slipping? Express your answer to two significant figures and include the appropriate units.

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.