Question #13c1f
1 Answer
While this physics problem is simple to describe, the answer is really rather complex. One must consider the vector force of the ladder on the floor and the ladder on the wall. Each will have a frictional force which is related to how much force is being applied perpendicular to each surface.
For simplicity, consider a ladder setup very poorly which makes a 45º angle with the floor and a wall. It would be very foolish to climb such a ladder and it may even slip on its own. But let's assume that the frictional forces allow it to stay in place. Take a step on a rung near the bottom and most of the force is exerted directly down toward the lower contact with the floor.
Next, think about stepping onto a rung near the top of the ladder. Here your weight exerts a force parallel to the wall and helps to push this end straight down the wall. The force on the floor acts from your standing point directly down the ladder and exerts a force on the floor at 45º. A portion of the force is perpendicular to the floor which can help the friction. But a large portion of the force is also pushing parallel to the floor causing the base to slip.
