Scientists often make measurements. The physical quantities they measure fall into two categories: scalars and vectors. Scalar and vector quantities are treated differently in calculations.

Part of

- Question
Find the distance travelled by Caitlyn if she sprints at an average speed of 9 m/s for 4 seconds.

d = s × t

Distance moved = 9 m/s × 4 s = 36 m

The distance travelled by Caitlyn is 36 m.

- Question
Find the time taken to cover 256 m at an average speed of 8 m/s.

t = d ÷ s

Time = 256 m ÷ 8 m/s = 32 s.

The time taken is 32 s.

- Question
Find the velocity of a train if it covers 1000 metres in a south direction in 25 seconds.

v = displacement ÷ time

The displacement = 1000 m south

Velocity v = 1000 m ÷ 25 s = 40 m/s south. Don’t forget the direction!

The velocity of the train is 40 m/s south.