Final answer:
Rigid-body displacements are movements of a solid object that do not change the object's size or shape, which means the statement provided is True. Displacement is a vector quantity, distinct from distance, which is a scalar.
Step-by-step explanation:
Rigid-body displacements refer to the movement of a solid object without any deformation. A displacement involves a change in the object's position in space, but the internal distances between any two points within the object remain unchanged.
To answer your question: Rigid-body displacements do not change the size or shape of a body. This statement is True. No matter if the body is translated (moved from one place to another) or rotated (spun around an axis), as long as we consider it to be a rigid body, its size and shape will remain consistent.
It is important to distinguish between concrete concepts like displacement and other related but different terms. Displacement as a vector quantity is different from distance, which is a scalar and only measures the magnitude of separation between two points regardless of direction. Moreover, velocity is a vector that describes the rate of change of displacement, whereas speed describes the rate of change of distance.