Car A runs a red light and broadsides Car B, which is waiting to make a left turn. Car A has a mass of 2,000 kg. Car B has a mass of 1,500 kg.

Car A runs a red light and broadsides Car B, which is waiting to make a left turn.  Car A has a mass of 2,000 kg. Car B has a mass of 1,500 kg. after the impact, the cars stick together and slide away at a speed of 9.1 m/s. How fast was Car A going when it hit Car B?