An air craft attempt to fly due north at 100 kmh-1. If the wind blows against it from east to west at 60 kmh-1, its resultant velocity is?
A
117 kmh-1, N31oE
B
127 kmh-1, N31oE
C
117 kmh-1, N31oW
D
127 kmh-1, N31oW
Verified Correct Answer: C.
Physical Principles & Numerical Solution
\(R^2 = 100^2 + 60^2\)
10000+3600 = 13600
R = \(\sqrt{13600}\) = 117km
60km & 100km = tan\theta = \(\frac{60}{100}\)
\(tan^{-1}\) 0.6
= 31º west of the North
117km N31ºw
Source: WAEC / JAMB / NECO Classroom Archive (Record #14496)