Which of the following is an example of a non-contact force?

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

Answer: (A)

Non-contact forces act on an object without touching it. Magnetic forces are a clear example because a magnet can attract or repel another object from a distance through the magnetic field. You’ve probably seen a paperclip jump toward a magnet or two magnets push apart without any physical contact.

Friction needs contact between surfaces to oppose motion, so it’s a contact force. Buoyancy arises from fluid pressure on the surface of an object that’s in the fluid, which also involves contact with the fluid. The support force (normal force) comes from a surface pushing on an object in contact. So magnetic forces stand out as the non-contact example.