Understanding Scalar and Vector Quantities

Physical quantities can be grouped into scalar quantities and vector quantities.
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.
Scalar quantities are physical quantities that have magnitude only.
Vector quantities are physical quantities that have magnitude and direction.
Some examples of scalar and vector quantities are listed in Table.
Scalar quantities Vector quantities
Length Displacement
Time Velocity
Temperature Acceleration
Mass Momentum
Speed Force

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.
From the above description, determine whether each of the quantities involved is a scalar or a vector quantity and explain your answer.
Solution:

Event	Quantity	Explanation
A warm night with a temperature of 30°C	Scalar quantity	Temperature has magnitude only.
3 hours of sleep	Scalar quantity	Time has magnitude only.
Hiking to the base camp 2 km away	Vector quantity	The magnitude of the distance and the direction of the hike are involved.