When the downhill force of gravity exceeds the internal frictional forces resisting motion, the material will move.
(the downhill force of gravity; exceeds; the internal frictional forces resisting motion) (the internal frictional forces; resisting; motion) (the material; will move; T:When the downhill force of gravity exceeds the internal frictional forces)
the downhill force of gravity the internal frictional forces the material
exceeds resisting will move
the internal frictional forces resisting motion
motion
T:When the downhill force of gravity exceeds the internal frictional forces