Answer:
The correct choice is C) 17.78 m/s
Step-by-step explanation:
According to the addition of vectors we add the magnitudes of vectors and the direction is seen in accordance to the resultanat vector. If the direction is same fro both vectors then simply the magnitude is added and direction remains the same. If the direction is opposite then the magnitude is subtracted. In the given two vectors the direction o f both the vectors is same so we simply add them as 12.57 + 5.21 = 17.78