Which force opposes the motion of a rolling object as it moves along a surface?

• A. Mass
• B. Rolling friction
• C. Velocity
• D. Air Resistance

Answer: (B)

When a wheel or ball rolls on a surface, friction at the contact point resists the motion. This rolling friction arises because the surfaces deform slightly and microscopic irregularities catch and push back as the object moves, producing a force that points opposite to the direction of travel. This is the main force that slows the rolling object along the surface. Mass is just a property related to inertia, not a resisting force by itself. Velocity is the rate of motion, not a force. Air resistance acts through the air and is usually less significant for a rolling object on a surface, so the primary opposing force is rolling friction.