Solve the given problem:
Problem: An SUV with a mass of 1.80×103 kg is travelling eastbound with a speed of +15.0 m/s, while a compact car with a mass of 9.00×102 kg is travelling westbound at -15.0 m/s. The vehicles collide head-on and stick together.
A- What is the speed of the wreck immediately after the collision, and which way does it move?
Please use as much detail as possible in your answer. Thanks.