Answer:
22.8 m/s at 17.4°
Explanation:
You want to find the resultant of ...
3 cis 0° +20 cis 20° = (3, 0) +(18.794, 6.840) = (21.794, 6.840)
The magnitude is the root of the sum of the squares of the velocities in the horizontal and vertical directions:
s = √(21.794² +6.840²) ≈ 22.8
The direction is found from the fact that the tangent of the angle is the ratio of vertical to horizontal coordinates:
angle = arctan(6.840/21.794) ≈ 17.4°
The resultant velocity is 22.8∠17.4° meters per second.