Guest Posted October 14, 2008 Report Share Posted October 14, 2008 "Two trains 200 km from each other are moving at the speed of 50 km/hour towards each other." I have a problem here. By definition if they are moving at 50km/h towards each other then they are each moving an average of 25kph. They are moving at the speed of 50 km/hour. That is describing the speed of each train. When we define the speed of a train, most of us do so with respect to the ground, not other moving objects. "Two trains are moving at the speed of 50 km/hour next to each other." We would say that each train is traveling at 50 km/hour because that's how fast they're traveling in respect to the ground. We wouldn't say they are traveling 0 km/hour. "Two trains 200 km from each other are moving at the speed of 50 km/hour towards each other." Each train is traveling at 50 km/hour in respect to the ground. Link to comment Share on other sites More sharing options...
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