**Q2: **

An airplane flying horizontally in a straight line moves parallel to the ground at a speed of 450 m/s. A second airplane flies below, in the opposite horizontal direction, moving parallel to the ground at a speed of 100 m/s. Which of the diagrams (a), (b), (c), and (d) correctly shows how the velocities of the airplanes can be combined to find the speed at which the airplanes move relative to each other?

- A(b)
- B(a)
- C(c)
- D(d)