Momentum question. Acceleration on a moving track

AI Thread Summary
The discussion revolves around the concept of speed accumulation on a moving track, specifically a train acting as a roadway. When a train moves at 100 mph and a vehicle on it accelerates to 100 mph in the same direction, the combined speed relative to the ground would indeed be 200 mph. The analogy of running on a travelator is used to illustrate this concept of speed addition. Clarifications are made regarding the instantaneous acceleration when joining the moving train. Overall, the participants confirm the understanding that speeds can be combined under these conditions.
Berts
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Hi,

I've a question that is baffling me a little.

If a train was made so that it would act as a moving track / roadway and the cars were connected so as to complete a length of the track, in an oval for example. Say we accelerate the moving trackway to 100 Mph, and then a car accelerates to 100mph. Total speed = 200mph.

Now say you have a moving track on top of the railway track. Are all of the speeds combined, is it even possible? Would I imagine it would be like running on a travelator? So long as you joined the train at 100mph would you instantly accelerate to 200 mph?
It is hurting my brain and I know something in my thinking is incorrect!
 
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Berts said:
So long as you joined the train at 100mph would you instantly accelerate to 200 mph?
How did that "instantly" come into this?
 
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A.T. said:
How did that "instantly" come into this?
Ah yes I see now,

But once on the train you could then accelerate the vehicle and go 200mph...
 
Berts said:
Are all of the speeds combined, is it even possible?
I assume you mean something like this: Say a train is moving at 100 mph East with respect to the ground/track. And you, on the train, are riding a motorcycle at 100 mph East with respect to the train. (Pretend it's a long flat bed train.) Then your speed with respect to the ground will be 200 mph.

Is that what you mean?
 
Doc Al said:
I assume you mean something like this: Say a train is moving at 100 mph East with respect to the ground/track. And you, on the train, are riding a motorcycle at 100 mph East with respect to the train. (Pretend it's a long flat bed train.) Then your speed with respect to the ground will be 200 mph.

Is that what you mean?
Yes thanks :-)
 
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