The principle of thin blade of kitchen knife is to reduce contact area and increase pressure.
Pressure = pressure/stressed area. From this formula, we can know that pressure and pressure are related to contact area. When the applied pressure is equal, the blunt the knife is, that is, the larger the contact area between the blade and the object, the smaller the pressure is. If you want to increase the pressure, you have to increase the intensity of application, so it is more difficult to cut the object. The sharper the blade, the thinner the blade, and the greater the pressure, so the object is easily cut off.
The center of gravity of the kitchen knife is in front of the handle. In order to improve the speed of waving the kitchen knife by using the lever principle, the instantaneous pressure is increased by using the inertia and impulse principle to cut hard objects.
When cutting soft objects (such as vegetable leaves), the tip of the knife often contacts with the chopping block as the fulcrum, and moves the blade up and down to cut. This is to use the lever principle to reduce the moving speed of the blade, thus improving the cutting accuracy. At the same time, the chopping block can bear part of gravity and improve the accuracy of wrist control.
Expanding knowledge: the correct posture of holding a kitchen knife
Generally, there are two ways to hold a kitchen knife, one of which is more common and the most standard.
When holding a knife, the index finger and thumb are on both sides of the handle, and the other three fingers naturally hold the handle. This method of holding the knife is relatively stable, not easy to shake, and more labor-saving.
The second method is to put the index finger on the back of the knife, hold the handle with other fingers, and use the touch of the index finger to make the cutting force more accurate.
Note: when cutting vegetables, the tip of the knife should not cut inward, but try to cut outward, that is, when cutting, the tip of the knife will cut farther and farther away from the fingertips, which can protect the fingers. But if you want to cut the kitchen knife quickly, you still have to operate it continuously for a long time.