Id be very grateful for any help with this relative velocity question: To a man walking North at 4m/s, a constant wind appears to have a speed f 3m/s. The man then changes direction, and when he is walking West at 3m/s the wind appears to have a speed of 4 m/s. There are two possible wind velocities. If I and j are unit vectors in the east and north directions, respectively: 1) Show that -3i + 4j is one possible wind velocity 2) Find the second possible wind velocity. Ok, so this is what I¡¦ve got so far: Vm (Velocity of man) = 4m/s = 4j m/s. (When wind appears to have Vw (Velocity of wind) of 3m/s) Vm (Velocity of man) =3m/s = 3i m/s (wind appears to have Vw (Velocity of wind) of 4m/s) Vm = 4j Vwm = xi Vw = ai + bj Vwm = Vw ¡V Vm Xi = ai + bj ¡V 4j Xi = ai + bj +0i -4j „Ã xi = ai „Ã x = a „Ã 0 = b ¡V 4 „Ã b=4 Vm = -3i Vwm = yi ¡V yj Vw = ai + bj Vwm = Vw ¡V Vm Yi ¡V yj = (ai + bj) + 3i „Ã yi = ai +3i „Ã -y = b „Ã y = -4 Y = a ¡V 3 -4 = a ¡V 3 1 = a This gives me a velocity of 1i + 4j. Have i gone totally wrong, or have i just found the answer to part two instead of part one? If so, what do i do next to find the second velocity, or, if its all just totally wrong, how should i actually go about doing the question? Thanks in advance for any help you can give.