In the experiment, the bottle, chopsticks and rice grains are tightly squeezed together due to the extrusion between the rice grains in the bottle and chopsticks, which increases the friction between the bottle, chopsticks and rice grains. So chopsticks can lift rice grains and bottles together.
characteristic
Friction is related to objects that rub against each other, so the description of friction in physics is not generalized, nor is it as accurate as other forces. Without friction, shoelaces can't be tied, and screws and nails can't fix objects.
The biggest difference of friction is the difference between static friction and other friction. Some people think that static friction should not actually be counted as friction. Other friction forces are related to dissipation, which reduces the relative speed of objects rubbing against each other and converts mechanical energy into heat energy.
Friction between solid surfaces can be divided into sliding friction, rolling friction, static friction, rolling friction and rotating friction. In engineering, people use lubricating oil to reduce friction. If two friction surfaces are separated by a layer of liquid, liquid friction will occur between them, and mixed friction may also occur if the liquid separation is incomplete.
Air cushion guide rail works by gas friction. The working principle of lubricating oil air cushion guide rail is to use "liquid or gas (that is, fluid) friction instead of solid friction" to work.