In this case two vectors are colinear and they have an opposite orientation.
N + ( - S ) = N - S = 1 m - 0.8 m = 0.2 m
Answer:
The total displacement is 0.2 m north.
No light does not need medium to travel.Its an electromagnetic(EM) wave.All EM waves travel independent of medium. In contrast mechanical waves need a medium,sound waves,shock waves are mechanical and they need medium to transfer energy or travel.
The answer is b fission hope this helps
