A privet plane is traveling due east at a rate of 150 mph. A south wind is blowing 50 mph. What is the actual velocity of the plane?
A. 141 mph
B. 158 mph
C. 172 mph
D. 200 mph
So we want to know what is the velocity of the private plane that is traveling east with velocity ve=150 mph and if the wind is blowing west with velocity vw=50 mph. So the overall velocity is v=sqrt(ve^2 + vw^2). Now we input the numbers: v=sqrt(150^2 + 50^2)=sqrt(22500+2500=sqrt(25000)=158.11 mph. So the correct answer is B. 158 mph.
