Introduction to Scalers

Many familiar physical quantities can be specified completely by giving a single number and the appropriate unit. For example, "a class period lasts 50 min,"or "the gas tank in my car holds 65 L,"or "the distance between the two posts is 100 m."A physical quantity that can be specified completely in this manner is called a scalar quantity. The w...

Physical quantities such as time, mass, and distance have magnitude, but no direction. Such quantities are called scalar quantities.

They are expressed as a numerical value followed by a physical unit. For example, the mass of an apple is 100 g. 

Scalars are different from vectors as vectors have both magnitude and direction.