Which term describes forces that do not require physical contact to act on an object?

• A. Friction
• B. Contact force
• C. Noncontact force
• D. Normal force

Answer: (C)

This question examines forces that can act on an object without needing to touch it. These are noncontact forces, also called action-at-a-distance forces. They can influence an object from a distance, without direct contact. Examples include gravity pulling on you from Earth, magnetic forces between magnets, and electric forces between charged objects. The term that fits this description best is noncontact force.

Friction, on the other hand, is a force that resists motion between surfaces in contact, so it requires contact. A contact force means any force that arises from direct touch, like a push or a pull when objects are touching. Normal force is the support force that a surface exerts on an object in contact, acting perpendicular to the surface. Neither of these describe forces that can act without contact.