Scalars and vectors - Higher
The direction of movement shows the difference between a scalarA physical quantity that has magnitude (size) only. Eg energy, temperature, mass, distance. and vectorA measurement having size (magnitude) and direction, eg a displacement of 4 m North. quantity – this is the difference between the speed of an object and its velocityThe distance travelled in one second in a specified direction..
- A physical quantity is something that can be measured.
- Scalar quantities only have size (or magnitude).
- Vector quantities have size and direction.
Speed is a scalar quantity - direction is not important.
Velocity is a vector quantity – direction is important.
Some scalar quantities you are likely to use in Physics are:
- mass
- distance
- speedThe distance travelled in a fixed time period, usually one second.
- rate of change of speed
- time
Some vector quantities you are likely to use in Physics are:
- displacementA distance measured in a specified direction.
- velocityThe distance travelled in one second in a specified direction.
- accelerationThe rate of change of velocity is measured in metres per second squared. Acceleration = change of velocity ÷ time taken.
- force
- weight