Final answer:
Friction is caused by a slight vibration, friction, or slippage between two contacting surfaces that are under stress and heavily loaded. When surfaces rub, the surface atoms adhere and cause atomic lattices to vibrate, creating heat. Chemical reactions can also occur between atoms and molecules on the surfaces, leading to frictional wear.
Step-by-step explanation:
Friction is caused by a slight vibration, friction, or slippage between two contacting surfaces that are under stress and heavily loaded. When surfaces rub, the surface atoms adhere and cause atomic lattices to vibrate, creating sound waves that penetrate the material. The sound waves diminish with distance and their energy is converted into heat. Chemical reactions can also occur between atoms and molecules on the surfaces, leading to frictional wear.