Question

An aeroplane flies 400 m north and 300 m south and then flies 1200 m upwards then net displacement is

• A. 1200 m
• B. 1300 m
• C. 1400 m
• D. 1500 m

Answer 1

The correct option is A 1200 m

An aeroplane flies 400 m north and 300 m south so the net displacment is 100 m towards
north.
Then it flies 1200 m upward so$r=\sqrt{(100{)}^2+(1200{)}^2}=1204m\simeq 1200m$

The option should be 1204m,because this value mislead one into thinking that net displacement is in upward direction only.