Page 16 -
P. 16
2.1 How do we know how far we have
moved? Distance and displacement
To get to school, you Describing movement
need to travel there When we are moving from one place to another, we always travel a
from home taking specific distance. The distance an object travels along a trajectory (or
textbooks nis edu kz
the shortest possible path) is called the distance covered or simply distance. It is denoted
route. You could walk by the letter d and measured in metres (m). The distance covered
depends on the trajectory we take to reach a specific location.
or take a bus. You
could choose a taxi, But it is also important to know the direction of movement. When
or even a helicopter! an object moves, we can take note of its initial position and its final
position. The numerical difference between the straight line that links
What do you think are
the final and the initial position is called the total displacement or
the similarities and
simply displacement.
differences between
To better understand the difference between distance and
the routes travelled in
displacement, look at the picture below. Think of the skier going down
these ways?
a mountain; they leave tracks as they travel through the snow. If we
want to measure the total distance travelled by the skier, we need to
measure the total length of the tracks they leave behind. But by simply
using a straight line connecting the start and the finish points of these
tracks, we can calculate the total displacement.
So
Total distance
travelled (d)
Sf So–Sf
INV Using string, explore the distance and displacement you cover
as you move around the classroom from one end to another, taking
different trajectories. Measure the total distance and your total
displacement for at least 3 different routes.
REMEMBER!
● Displacement is a straight line that links the starting position and
the final position of an object. Displacement has both magnitude
and direction because the object has moved in a specific way.
● Distance is the total length of the trajectory that an object follows
during its motion. Distance has only magnitude (i.e. a value).
16
