Physics - Vectors Question with Solution | TestHub

A unit vector has a magnitude of one and is used to specify direction. It is dimensionless because it is obtained by dividing a vector by its magnitude.

The dot product of two orthogonal unit vectors (e.g., $\hat{i}\cdot \hat{j}$) is zero, as the angle between them is $90^{\circ }$ and $\cos (90^{\circ })=0$. The dot product of a unit vector with itself (e.g., $\hat{i}\cdot \hat{i}$) is 1.