1. The problem statement, all variables and given/known data 1: An immobile person sees a package falling to the ground. It appears to be falling (a) at an angle, and (b) at speed V1. 2: A pilot flying horizontally at constant speed sees the same package. It appears to be (a) falling vertically, and (b) at speed V2. The question is: What's the speed of the pilot relative to the ground? 2. Relevant equations -- 3. The attempt at a solution If the pilot is flying horizontally and sees the package falling straight down, it would suggest to me that his own horizontal velocity matches that of the package. I attempted to sketch this out, and it strongly resembles a vector addition problem where the magnitude would be equal to sqrt(x^2 + y^2), which leads me to believe that the correct answer would be sqrt(v1^2 + v2^2) (C, below). I'm not 100% on this, though, since I seem to be having a hard time visualizing this beyond that. This is a multiple-choice question: A. v1 + v2 B. sqrt(v1^2 - v2^2) C. sqrt(v1^2 + v2^2) D. v2 - v1 E. v1 - v2 Am I going about this the proper way / am I right on this one, or am I a bit... off?