A Car moving North at 9 m/s strikes a stationary car of equal mass. The first car moves off after the collision at an angle of 30 degrees West of North, with a speed of 6 m/s.
What is the speed of the second car after the collision?
My resources have poor explanation of what to do. From what I gathered, I'm supposed to use:
V1^2 = V1'^2 + V2'^2 - 2V1'V2'CosTheta
9^2 = 6^2 + V2'^2 - 2(6)(V2') Cos30
81 = 36 + V2'^2 - 10.39(V2')
0 = V2'^2 - 10.39 (V2') - 45
Am i Supposed to go into Pythagorean's theory? Frankly I'm just lost.