When does the cornstarch and water mixture act like a solid?

When the mixture of cornstarch and water is subjected to a force that is applied quickly, it behaves like a solid. This phenomenon is known as the shear thickening effect or dilatency. Under rapid stress or deformation, the cornstarch particles experience increased friction and interlocking, causing them to form a rigid structure that temporarily resists the flow of the mixture. This transformation from a liquid-like to a solid-like state is the defining property that gives cornstarch its unique non-Newtonian fluid behavior.