Newton's Third Law and Normal Force

Steps:

• The object exerts a force on the slope due to the component of gravity perpendicular to the surface.
• By Newton's third law, the slope exerts an equal and opposite force on the object.
• Since the slope is frictionless, this reaction force has no parallel component and acts solely perpendicular to the surface.
• The direction of this normal force points upward, away from the slope's surface.

Why C is correct:

• The normal force is defined as the perpendicular reaction to the contact surface, balancing the perpendicular component of weight.

Why the others are wrong:

• A: Vertical upward ignores the incline; it would only apply on a horizontal surface.
• B: Parallel to the slope represents friction, absent here.
• D: Toward the slope contradicts the repulsive nature of the normal force.

Final answer: C