1. The problem statement, all variables and given/known data Car two is traveling due North and collides with Car one, which is traveling due west. Car One has a mass of 765kg and after the collision it travels at 70km/h, 57 degrees North of West. Car two has a mass of 1100kg and after the collision it travels at 41km/h, 44 degrees North of West. What is the velocity of each car right before impact? So Car One - m1 = 765kg, v1f = 70km/h Car Two - m2 = 1100kg, v2f = 41km/h 2. Relevant equations Pyi = Pyf Pxi = Pxf P = mv SINE LAW 3. The attempt at a solution So, I started by constructing a vector triangle for each car, and using the sine law to determine the other sides. CAR ONE TRIANGLE Where one side is the west (x plane/ P1) momentum and one side is the north (y plane/P2) momentum. The hypotenuse (p12) is the final momentum of car one after the collision. P12 = mv =(765kg)(70km/h) =53550 kgxkm/h cos = adjacent/hypotenuse = cos44 = P1/53550 P1 = 38520.64...kgxkm/h sine = opposite/hypotenuse =sine44 = P2/53550 P2 = 37198.95...kgxkm/h CAR TWO TRIANGLE Much the same as the first triangle, except the hypotenuse of this triangle represents the final momentum of the second car. P12 = mv = (1100kg)(41km/h) 45100kgxkm/h cos57 = P1/45100 P1 = 24563.22...kgxkm/h sine57 = P2/45100 P2 = 37824.04...kgxkm/h Okay, up to this point, I'm fairly confident that I'm on the right track. It's right here where I'm getting confused. I know I need to add the vector components, but I'm not entirely certain how. So... Pyi = Pyf Py1 = P2 + P2 =37198.95...kgxkm/h + 37824.04...kg x km/h = 75022.99...kgxkm/h Pyf = final momentum of car two = 45100 kgxkm/h ...They do not match. I have accomplished nothing. My teacher assures me I am using the correct formula, but clearly, I am using it incorrectly. What am I doing wrong?