# Scalars and VectorsScalars and Vectors

A Scalar quantity is a quantity which only has magnitude. Some examples of Scalar quantities
are:
o Mass
o Time
o Temperature
o Length
o Speed
o Energy
>A Vector quantity is a quantity that has both magnitude and direction. Some examples of Vector
quantities are:
o Displacement
o Force
o Velocity
o Acceleration
o Momentum
> Both Vectors and Scalars have magnitudes, and sometimes the same units, like in the case of
Speed and Velocity. However, vectors have a direction and scalars do not.
> Vectors can be added together to find the resultant vector. For vectors acting along the same line
of action, can simply be added or subtracted from each other depending on its direction.
> For two vectors that are at right angles to each other, they should be drawn from head to tail,
and then using Pythagoras’ Theorem, the resultant vector can be calculated. The resultant vector
is one vector that produces the same overall effect that several vectors could produce.
> For vectors that form non-right angle triangles, then the cosine rule and the sine rule can be used
to work out any unknown lengths.
> A scaled drawing can also be used to work out the resultant vector by drawing a system to scale
and using it to work out distances.
> Vectors can also have horizontal and vertical components. When we find
the components of a vector, it is called resolution.
> Use these formulas to resolve a vector into two perpendicular
components; Fx = F cos Θ; Fy = F sin Θ.