Explain the vector–scalar distinction as it applies to displacement, distance, velocity and speed.
BEEZYREVISOR
GCSE Physics Revision
Learn it. Recall it. Revise it.
GCSE Physics revision
Velocity
Describing motion along a line
Your specification
AQA student objectives
Learning pathway
All · Most · Some
Apply the scientific explanation of velocity to a relevant example.
Analyse a new situation involving velocity and explain the scientific reasoning.
Revision summary
Key knowledge
Read on screen, then print for Cornell-style active revision.
Scalar vs Vector Quantities
- Speed is a scalar quantity because it only has magnitude (size) and no direction.
- Velocity is a vector quantity because it has both magnitude and direction.
- Including direction in a measurement is what distinguishes a vector quantity from a scalar quantity.
Calculating Velocity: A Worked Example
- To calculate velocity, divide the distance travelled by the time taken and then state the direction of travel.
- For example, a person walking 50 m south in 40 s has a velocity of 50 / 40 = 1.25 m/s south.
- Always include the unit (m/s) and the direction in your final answer when stating velocity.
Velocity of an Object Moving in a Circle
- An object moving in a circle at a constant speed is continuously changing direction, which means its velocity is constantly changing.
- Even though the speed remains the same, the change in direction means the velocity is not constant.
- This principle also applies to objects travelling around part of a circle, such as a car going around a corner.