When the external force increases, non-Newtonian fluid. The faster the speed, the harder it will become, so that you can turn the gum into a cone and hit it on the coconut. Cone-shaped chewing gum has small stress area and high pressure, so when the chewing gum hits the coconut at a very fast speed, its hardness will be very high due to its non-Newtonian fluid characteristics, so the coconut can be easily opened.
Non-Newtonian fluid refers to a low viscosity fluid, which will undergo high deformation after being stressed, and its shear stress is proportional to the strain rate. It has the characteristics of non-Newtonian fluid, that is, the greater the external force, the harder it becomes and the more difficult it is to deform. Non-Newtonian fluids widely exist in life, production and nature.
Most biological fluids are now defined as non-Newtonian fluids. Body fluids such as blood, lymph and cystic fluid, as well as "semi-fluid" like cytoplasm, are all non-Newtonian fluids.
Concentrated solutions and suspensions of high molecular weight polymers are usually non-Newtonian fluids. Polyethylene, polyacrylamide, polyvinyl chloride, nylon 6, PVS, cellophane, polyester, rubber solution, various engineering plastics, chemical fiber melting agents and solutions all belong to non-Newtonian fluids. Oil, mud, coal slurry, ceramic slurry, paper pulp, paint, ink, toothpaste, silk regeneration fluid, well washing fluid, drilling and completion fluid, magnetic mud, coating fluid of some photosensitive materials, foam, liquid crystal, high sand water flow, landslide, mantle, etc. They are also non-Newtonian fluids.