Scalar and vector quantities

This section introduces scalar and vector quantities. Understanding these terms is necessary for describing motion, interactions, and the effects of forces on objects.

Scalar quantities

• Have magnitude only (no direction).

• Examples:

  1. Speed: A car moving at 60 km/h (magnitude only).

  2. Mass: An object weighing 5 kg.

  3. Temperature: 25°C.

• Scalars are sufficient to describe "how much" of something exists.

Vector quantities

• Have both magnitude and an associated direction.

• Examples:

  1. Velocity: A car moving at 60 km/h north (magnitude + direction).

  2. Force: A 10 N push applied at an angle of 30°.

  3. Displacement: Moving 10 meters east.

Representation of vectors

• Vectors are often illustrated using arrows:

  • Length of Arrow: Represents the magnitude.

  • Direction of Arrow: Represents the direction of the vector.

• Example: A vector showing a force of 5 N directed upwards will have an arrow pointing vertically with a proportional length.

Practical examples of scalars and vectors