Question

A runner traveled 15 kilometers north then backtracked 11 kilometers south before stopping. His resultant displacement was

Answer 1

displacement is 4 km in north direction.

Explanation:

we are given

 A runner traveled 15 kilometers north first

then backtracked 11 kilometers south

we have to find displacement=d=?

assume that  east side represents +ve x- axis(horizontal)

and

north represent +ve y - axis (vertical)

we can take  x-axis (horizontal) as  i

and y-axis (vertical) as j.

Displacement = 15 j -11 j = 4 km north

Answer 2

Answer:

 Resultant displacement is 4 km north.

Explanation:

    Let east represents positive x- axis and north represent positive y - axis. Horizontal component is i and vertical component is j.

   A runner traveled 15 kilometers north then backtracked 11 kilometers south before stopping,

   So initial displacement, 15 kilometers north = 15 j km

        Second displacement, 11 kilometers south = -11 j km

   Total displacement = 15 j -11 j = 4 j km

   Total displacement is 4 km north.