Which option describes a non-contact force?

• A. Buoyancy
• B. Friction
• C. Support
• D. Magnetic forces

Answer: (D)

Non-contact forces act at a distance, without touching the object. Magnetic forces fit this idea because magnetic fields extend through space, allowing objects to attract or repel without any physical contact. You can see this with magnets pulling on metal objects or repelling each other even when there’s a gap between them—the force is felt through the field, not through contact.

In contrast, buoyancy requires fluid to push on the object's surface, so contact with the fluid is involved. Friction happens where surfaces rub against each other, opposing motion, which is also contact-based. The support force (normal force) is the push from a surface on an object pressing against it, another contact interaction.

Therefore, the non-contact force described is magnetic forces.