High School Pre-Cal

Question

According to its instruments, a plane is flying northwest at 400 mph. Outside the plane there is an 80 mph wind blowing from north to south. What is the resulting direction of the plane?


A.about 34° north of west

B.about 36° north of west

C.about 38° north of west

D.about 40° north of west

Answer 1

Kenneth,

 

I was really someone else would attempt this but here goes.

 

vector 1 =(400cos135, 400sin 135)

 

 = (-282.84, 282.84)

 

vector 2 = (80cos270, 80sin270)

 

 = (0, -80)

 

add the vectors

 

(-282.84, 202.84)

 

tan^-1(202.84/-282.84) = 54.35º

 

subtract this from 90 to get correct angle

 

90 - 54.35 = 35.65 which rounds to 36º

 

amswer C