The only vertical force on the person-ladder system is the force up from the floor.
Therefore this vertical force up must balance the weight of the person plus the ladder.
Fup = 310 + 515 = 825 N
Now if you asked for the HORIZONTAL force from the wall on the ladder, then we would have had to do moments.
An 8.5 m ladder whose weight is 310 N is placed against a smooth vertical wall. A person whose weight is 515 N stands on the ladder a distance 1.8 m up the ladder. The foot of the ladder rests on the floor 5.78 m from the wall.
Calculate the normal force exerted by the floor on the ladder.
Answer in units of N
1 answer
1 answer