Answer:
Step-by-step explanation:
The north direction is towards the positive y direction on the coordinates axis and the south is towards the negative direction of the coordinate axis.
If a duck flies at 15 m/s due south against a gust of wind, then the duck velocity will be -15m/s
If the wind is blowing at 5 m/s due north, the velocity of the wind will be +5m/s
The resultant velocity of the duck will be the sum of the velocity along the y - component = -15 + 5 = -10m/s
Hence the resultant velocity of the dock is -10m/s