What can friction be divided into?
2 Answers
There are many types of friction. According to the movement form of the friction pair, friction can be divided into sliding friction and rolling friction. The former is the friction when two mutually contacting objects have relative sliding or a tendency of relative sliding, while the latter is the friction when two mutually contacting objects have relative rolling or a tendency of relative rolling. The conditions that must be ensured when calculating these two types of friction are: the object is in a state of rest or uniform linear motion, at which point the frictional force is equal to the resistance experienced by the object. Under the same conditions, rolling friction is less than sliding friction. According to the lubrication state of the friction surface, friction can be divided into dry friction, boundary friction, and fluid friction. Friction can also be divided into external friction and internal friction. External friction refers to the friction when the surfaces of two objects move relative to each other; internal friction refers to the friction between molecules within an object. Friction belongs to internal friction. Dry friction refers to the friction when the surfaces of the friction pair are in direct contact and there is no lubricant present.
Friction can generally be divided into two main types: static friction and kinetic friction, the latter of which includes sliding friction and rolling friction. From a driving perspective, I find this particularly important, especially when discussing the interaction between tires and the road surface. For example, when I apply the brakes, friction occurs between the brake pads and discs, starting with static friction to prevent the wheels from suddenly locking up, then transitioning to sliding friction to slow the car down. If the friction is too low, such as when driving on wet and slippery roads in the rain, the vehicle is prone to skidding and accidents, increasing safety risks. Additionally, rolling friction comes into play during normal tire rotation, affecting fuel consumption and wear. During routine maintenance, I always remember to check the tread depth of the tires to ensure the friction material isn’t excessively worn, as poor braking performance could result. Learning these concepts helps me pay more attention to road and vehicle conditions while driving, avoiding potential dangers—after all, prevention is better than regret.
