What is the magnitude of the resultant vector?

Question

a pedestrian walks a rate of 6km per hour east. The wind pushes him northwest at a rate of 13 km. per hour. Find the magnitude of the resultant vector

Answer 1

Assuming that by northwest you mean 135° from east, the components of the resultant vector are

 

u = (6 + 13cos135°) km/hr = -3.192 km/hr

v = (0 + 13sin135º) km/hr = 9.192 km/hr

 

√(u² + v²) = √[(-3.192)² + (9.192)²] km/hr ≅ 9.73 km/hr