3 MOTION IN 3 DIMENSIONS 3.12 Relative velocity
×− 1
if vg (^) x < 0. These expressions can be derived from simple trigonometry. For the
case in hand, Eq. (3.60) is the relevant expression, hence
φ = 180 ◦ (^) — tan
1.997 102
2.101 × 102
(^) = 136.5◦
. (3.61)