Mizukawa looked at the three of them and said, "I think you should have seen a car, right?" So, have you seen the tires underneath the car? What do those dense dimples do?

Liuzi Feng began to think about it, and the other two didn't compete with him. It was about two minutes before he spoke: it was clear that the grooves were used to increase friction. We've talked about friction and shape before, but what kind of shape increases friction? There is a hollow body on the surface. In fact, this geometry can only increase the friction between the concave and the convex grain, and the area between the concave and embossed grain is basically unaffected and the friction is relatively low.

Dueñas can't wait: of course, the groove has the effect of increasing friction. But that's not all it does. Having a void on the surface can indeed increase friction, and having a spike on the surface can also do it. So, why didn't car manufacturers choose the shape of a tire with a puncture body on the surface? Because the shape of the tire should ensure that the tire has a lot of movement, and there is a puncture body on the surface that cannot do it. Increasing friction is only an auxiliary purpose, while the main purpose of a person is to make the tires move.

Margarita was a little unimpressed: "What you said is a function of the tire, but it also has a function of keeping the pressure inside the tire stable. We all know that tires are inflated. In the process of movement, the gas inevitably has to move. If this happens, the tires will become extremely unstable. When the depressed part reaches the ground, the ground gives tremendous pressure to the edges of the depressed part. As a result, the edges are compressed inward. Then, there was a movement gas inside the tires that were suddenly suppressed. When the indentation leaves the ground, the recess reverts to its original shape. And the suppressed gas began to move again. After a short period of time, another depression reaches the ground, repeating the process of the previous depression. As a result, the gases inside the tires become stable.

Mizukawa said, "You haven't finished yet." We know that the greater the drums in the tire, the greater the friction. However, friction is too general. Friction is generated by friction, which can be classified as plane friction, inclined plane friction, and air friction. Since the air friction is generally very small, it will not be discussed here for the time being. Plane friction is smaller than inclined friction, so the corresponding car tire is much less dimple. Bevel friction can be further divided into gripping friction and sliding friction. If an uphill slope is connected to a downhill, then their gripping friction and sliding friction are of the same magnitude. The direction is reversed, though. If the car is going uphill, the grip friction must be particularly large. Therefore, it is appropriate to increase the grip friction between the tire and the uphill surface. Whereas, on the downhill slope, the car moves fast due to the high sliding friction. For safety, this is where the brakes need to be held. When the brake elements rub against the surface of the tire, the car slows down.

Of course, it is not excluded that the dents of the tires have an effect on air friction.

Dueñas suddenly exclaimed: "Yes, the grooves of the tires must have the effect of reducing sliding friction. So, the relationship between friction and motion is complex. Specific situations need to be treated on a case-by-case basis, and there is no standard correspondence.

Mizukawa looked at the three of them before saying: I don't think you have anything to add, so let's discuss it here today.