1. The problem statement, all variables and given/known data solve this change in velocity when the V2` = 19.04 m/s [S59W] and V2=16.32 m/s [S36W] 2. Relevant equations 3. The attempt at a solution I solved this using the components method first, for which i got the answer 7.536 m/s [W 26.78 N] And now for the vector subtraction piece: I did this diagram: http://s1176.beta.photobucket.com/user/LolaGoesLala/media/dffdfd.jpg.html So this is what i did I used cosine law like this: Δv^2 = (19.04)^2 + (16.32)^2 -2(19.04)(16.32)cos23 Δv= 7.536 then i used sine law like this: 7.536/sin23 = 19.04/sinx for x = 81° and then when i place it into the diagram and subtract 36 from it, i get 45°. So obviously it would be [W 45 N] but by using the components method i get a totally different angle why?