# Scalar vs Vector Quantities

### The Scalar Quantity

The scalar quantity is any positive / negative physical quantity that can be completely specified by its magnitude.

ex. Time , Length , Mass

### The Vector Quantity

The vector quantity is any physical quantity that can not be completely specified unless we know both its magnitude & direction.

ex. Force , Moment

### How to represent a Vector

Graphically:-

• Length of arrow = Vector's magnitude.
• Tip / head of arrow = The sense of vector's direction.
• The angle θ between the vector & a fixed axis = The direction of the vector.

In print:-

• A (boldfaced) = the vector.
• A (Italicized) = the vector's magnitude.

Handwriting:-

• ̅A (arrow or line above) = the vector.
• A (no arrow or line above) = the vector's magnitude.