1. The problem statement, all variables and given/known data Two cars leave the same point at the same time, each travelling at the same constant speed of 89.0 km/h and each having the same mass. However, the first car drives directly east, while the second car heads directly south. At what speed (the magnitude of the velocity) is the centre of mass of these two cars travelling? Give your answer as a positive value in m/s (without a sign). 2. Relevant equations I have attempted this using trigonometry, but have yet to come up with an answer that is correct. 3. The attempt at a solution 89 km/h = 24.72m/s Car 1: 24.72m/s [E] Car 2: 24.72m/s I have tried vector addition, and sin law. Any suggestions? Never mind it's been figured out. sin45(24.72)/sin90 = 17.479m/s -> magnitude of the cars speed.