Vectors and scalars. A scalar is an ordinary number a magnitude without a direction may have units (kg)or be just a number usually indicated by a regular letter, no bold face and no arrow on top Note: the lack of specific designation of a scalar can lead to confusion The product of a vector and a scalar is another vector in the same direction but with modified magnitude A=-0.75B B A Physics 121: Lecture 5, Pg 11Physics 121: Lecture 5, Pg 11 Vectors and scalars: A scalar is an ordinary number. a magnitude without a direction may have units (kg) or be just a number usually indicated by a regular letter, no bold face and no arrow on top. Note: the lack of specific designation of a scalar can lead to confusion The product of a vector and a scalar is another vector in the same direction but with modified magnitude. A A B = -0.75 B