The property of the jam to follow your hand is viscosity - the jam does not flow, even though you push it, but follows your hand instead. The jam will follow your hand and the cube will be distorted. If you put this jam cube onto a plate, then touch the top of the cube with your hand, and pull your hand parallel to the surface of the cube in any direction - you will be acting on the jam cube with a force that causes shear stress. For example, imagine a substance so viscous, that it can retain its shape, say a cube, for several minutes almost without changing - like a very viscous fruit jam.
Viscosity is often talked about in the context of shear stress, where shear stress is defined as stress that results from a force that acts parallel to the cross-section of the object. Dynamic or absolute viscosity measures the resistance inside of the fluid and is independent of the density of this fluid. Viscosity is a property of a fluid to resist the force that pushes the fluid to flow. Pouring viscous cream into a cup of non-viscous coffee
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