Final answer:
Normal stress acts perpendicular to the surface of an object, not parallel, therefore the statement is false.
Step-by-step explanation:
The statement that normal stress acts on a surface that is parallel to the internal force of the member is False. Normal stress is a type of stress that occurs on a material when a force is applied perpendicular to the surface of the object, not parallel. This is in contrast to shear stress, which is caused by forces that are parallel to the surface. When an object is either in tension or compression, the deforming force acts along the length of the object and is perpendicular to the cross-section; this deforming force is not parallel to the force causing the stress.