Home › UAE MoE Grade 12 › Physics › Friction, Drag and Elasticity › Why do two surfaces become warm when they are ru…
Why do two surfaces become warm when they are rubbed together?
AAtomic lattices are set vibrating
BThe surfaces gain mass by rubbing
CFriction creates new atoms of heat
DThe normal force turns into light
Answer & Solution
Correct answer: A. Atomic lattices are set vibrating
1. Atoms in a solid are linked to one another in lattices.
2. When surfaces rub, the surface atoms stick briefly and set those lattices vibrating.
3. Those vibrations travel into the material as sound waves.
4. The waves die away with distance and their energy ends up as heat, so the surfaces warm.
_Source: OpenStax College Physics (CC BY 4.0), Ch 5 "Further Applications of Newton's Laws: Friction, Drag, and Elasticity", section Making Connections: Submicroscopic Explanations of Friction_
Related questions
The tip of a probe dragged across a material is deformed by atomic-scale friction. The forWhat happens to the downward force of gravity on a skydiver as their speed rises?Which two forces act on a skydiver falling through air, once buoyancy is ignored?What would a nearly friction-free environment save on a large scale?What kind of characteristics of friction are the simple rules taught at school?Which of these is the standard everyday example of kinetic friction acting?Adding a heavy box on top of a crate makes it harder to push. Why?Oiling a concrete floor makes a crate easier to move. What has changed?