PLTW Principles of Engineering (POE) Practice Exam

Vector quantities are defined by having both magnitude and direction, which is fundamental to their characteristics. For example, velocity is a vector quantity because it specifies how fast an object is moving (magnitude) and in what direction it is moving. This dual aspect allows vectors to effectively represent various physical phenomena, such as force, which also involves both how strong the force is (magnitude) and in which direction it is applied.

The other options do not accurately capture the essence of what differentiates vectors from scalars. Scalars are described by magnitude alone, such as temperature or mass, and do not include direction. The notion that vectors result from physical motion is misleading since both vector and scalar quantities can exist without motion; they simply represent different physical attributes. Lastly, the claim that scalars cannot be measured is incorrect, as scalars can be measured and quantified, just lack the directional component. Thus, the defining characteristic of vector quantities is their inclusion of both magnitude and direction.