Final answer:
No, it is not possible to rest a ladder against a rough wall when the floor is frictionless, because static friction is necessary to prevent the ladder from sliding. Therefore, the correct answer is b) No.
Step-by-step explanation:
The question asks if it is possible to rest a ladder against a rough wall when the floor is frictionless. According to the principles of static equilibrium, a ladder requires sufficient friction at the base to prevent it from sliding when it is resting against a wall.
Without friction at the base, there is nothing to counterbalance the horizontal component of the ladder's weight, which would cause the ladder to slide outwards. When the floor is frictionless, it is not possible to rest a ladder against a rough wall.
The reason is that in order for the ladder to remain in equilibrium, the force of static friction between the ladder and the floor must be greater than or equal to the force that the ladder exerts on the wall.
Hence, no, it is not possible to rest a ladder against a rough wall when the floor is frictionless, since the static friction at the floor is crucial for maintaining the ladder's stability.