Question

Vector u has a magnitude of 5 units and a direction angle of 30°. Vector v has a magnitude of 7 units and a direction angle of 120°. What is the direction angle of their vector sum?

A. 82.21°
B. 84.46°
C. 85.11°
D. 86.13°

Answer 1

Answer: B. 84.46°

Step-by-step explanation: I got this correct on Edmentum.

Answer 2

B. 84.46°

Explanation:

Since the vectors are at right angles to one another, even a crude diagram will quickly show you that the direction of the sum is ...

30° + arctan(7/5) ≈ 84.4623° ≈ 84.46°