Understanding Scalar and Vector Quantities

Understanding Scalar and Vector Quantities

Understanding Scalar and Vector Quantities 1

  1. Physical quantities can be grouped into scalar quantities and vector quantities.
  2. Above Figure shows a truck travelling a distance of 50 km in the eastward direction. We describe the journey of the truck by stating the magnitude and the direction of its travel:
    (a) The magnitude is 50 km.
    (b) The direction is East.
  3. Scalar quantities are physical quantities that have magnitude only.
  4. Vector quantities are physical quantities that have magnitude and direction.
  5. Some examples of scalar and vector quantities are listed in Table.
    Scalar quantitiesVector quantities
    LengthDisplacement
    TimeVelocity
    TemperatureAcceleration
    MassMomentum
    SpeedForce

Example 1
Mei is putting up a night at a campsite during her training program. It is a warm night with a temperature of 30°C and she will have only 3 hours of sleep before hiking to the base camp of the mountain located 2 km away.
Understanding Scalar and Vector Quantities 2From the above description, determine whether each of the quantities involved is a scalar or a vector quantity and explain your answer.
Solution:

EventQuantityExplanation
A warm night with a temperature of 30°CScalar quantityTemperature has magnitude only.
3 hours of sleepScalar quantityTime has magnitude only.
Hiking to the base camp 2 km awayVector quantityThe magnitude of the distance and the direction of the hike are involved.

scalars, Vectors and Matrices