Explain Scalars and Vectors

This is one of the harder ideas to get used to when you start learning physics. The trick is to see that there is one basic difference between a scalar and a vector.

A scalar can be described by only a number and a unit, sometimes, these two are lumped together and called the magnitude.

Here are some scalar quantities:

• 54 m
• 28.97 cm/s
• 233.89 km/h

Vectors are a scalar quantity plus another part which tells the direction. To wrote a vector you need the number and unit part, magnitude plus a direction. When vectors are being represented by letters the letters appear in bold face like x, a, and i, and scalars will be standard letters like x, a, and i.

• d = 34.7 m, due North
• v = 66.0 m/s, 120 degrees

Example: your position from a certain point on a map is a vector, needs size and direction included, whereas your temperature only needs a size.  Don't sweat this now just refer to it later when it comes up.