physics notes

SCALAR AND VECTOR QUANTITIES Scalars are quantities that have magnitude only; they are independent of direction. Vectors have both magnitude and direction.  The length of a vector represents magnitude.  The arrow shows direction. EO 1.1 DEFINE the following as they relate to vectors: a. Scalar quantity b. Vector quantity Scalar Quantities Most of the physical quantities encountered in physics are either scalar or vector quantities.  A scalar quantity is defined as a quantity that has  magnitude only.  Typical examples of scalar quantities are time, speed, temperature, and volume.  A scalar quantity or parameter has no directional component, only magnitude.  For example, the units for time (minutes, days, hours, etc.) represent an amount of time only and tell nothing of direction.  Additional examples of scalar quantities are density, mass, and energy. Vector Quantities A vector quantity is defined as a quantity that has both magnitude and direction.  To work with vector quantities, one must know the method for representing these quantities. Magnitude,  or  "size"  of  a  vector,  is  also referred to as the vector's "displacement."  It can be thought of as the scalar portion of the vector and is represented by the length of the vector.    By  definition,  a  vector  has    both magnitude and direction.  Direction indicates how  the vector is oriented relative to some reference axis, as shown in Figure 1. Using  north/south  and  east/west  reference axes,   vector   "A"     is   oriented   in the     NE quadrant with a direction of 45  north of the o EW  axis.  G  iving  direction  to  scalar  "A" makes  it  a  vector.    The  length  of  "A"  is representative of its magnitude or displacement