Answer: True
Explanation:The shear stress is a force that causes layers of a substance to slide above each other in opposite direction, it is usually represented by (tau) the THE SHEER STRESS IS DIRECTLY PROPORTIONAL TO THE VELOCITY GRADIENT. AT THE CENTER OF A PIPE DURING A LAMINAR FLOW, THE VELOCITY GRADIENT IS ALWAYS ZERO.
sheer stress is the main cause of downward movement of the materials of the earth and it is the leading cause of earthquakes.
