Two trains are moving towards each other from opposite directions. One is travelling at 80km/h and one is travelling at 70km/h. What is the speed of the two trains relative to each other in km/h? Explain how you came to this answer and show your working out.

Ben (55kg) is standing on very slippery ice when junior (25kg) bumps into him. junior was moving at a speed of 8 m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision. give the answer in m/s. describe the work you did to get the answer.