# Scalar and vector

A scalar has size only, like 5 kg. A vector has size and direction, like 5 N to the left.

Physics (school) · Part 01: Motion and measurement · Card 2 of 8 · Last updated 2026-10-19

## Analogy

A scalar is 'drive 10 km'. A vector is 'drive 10 km north'.

## Example

**Walk to school**

Walk 300 m east, then 400 m north.
Distance = 300 + 400 = 700 m (scalar)
Displacement = 500 m, straight line
(a 3-4-5 triangle) (vector)

## In practice

Forces, velocity and displacement are vectors. Mass, time, speed and energy are scalars.

## Practice

### Flashcards

- **What is the difference between speed and velocity?** Velocity is speed in a given direction. Speed has no direction.
- **Name one scalar and one vector.** Scalar: mass or speed. Vector: force or velocity.

### Interview questions

**Explain the difference between distance and displacement, with an example.**

- Distance is the total path length and is a scalar
- Displacement is the straight-line change in position and is a vector
- Example: a full lap has distance but zero displacement

## Questions people ask

### What is the difference between distance and displacement?

Distance is the total length of the path you travelled, and it has no direction. Displacement is the straight-line gap from start to finish, with a direction. If you run one full lap of a track, your distance is the lap length but your displacement is zero.

### How do you show a vector on a diagram?

Draw an arrow. The length of the arrow shows the size, and the way it points shows the direction. A force of 10 N should have an arrow twice as long as a force of 5 N pointing the same way, so you can compare them at a glance.

## Related concepts

- [Velocity](https://studyvisually.com/learn/science/physics-school/physics-school-part-1/physics-school-part-1-concept-4)
- [SI units](https://studyvisually.com/learn/science/physics-school/physics-school-part-1/physics-school-part-1-concept-1)

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