Question

Write the resultant displacement:
(a) P covered 10 km due east, and then 15 km due west.
(b) Qcovered 20 km due north and then 20 km due south.
(c) R covered 15 km due west and then 30 km due east.
(d) Scovered 35 km due south and then 45 km due north.​

Answer 1

Answer:

a.

10 i + ( - 15 i )

Net displacement = - 5 i [ west ]

b.

20 j + ( - 20 j )

Net displacement = 0

c.

- 15 i + 30 i

Net displacement = 15 i [ east ]

d.

- 35 j + 45 j

Net displacement = 10 j [ north ]

Here i and j are unit vector :

For more easy understanding :

Positive x - axis or east direction taken as  ' + i '

Negative x - axis or west direction taken as ' - i '

Positive y - axis or north direction taken as ' + j '

Negative j - axis or south direction taken as ' - j '