Solving the Debate: How Fast Am I Going?

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When running toward the front of a bus traveling at 65 mph, your speed relative to the road is 77 mph, while relative to the bus, it is 12 mph. The debate hinges on the concept of relative motion, where speed is defined based on the observer's frame of reference. The discussion highlights Galileo's relativity, emphasizing that speed is not absolute but relative to the observer. The true speed, accounting for relativistic effects, is slightly less than 77 mph. Thus, the conclusion is that the original claim of traveling at 77 mph is correct in the context of road speed.
laytonsdad
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My wife and I have had a debate going for some time now.

If I am on a bus going 65 mph and I run tword the front of the bus at 12 mph, at that point how fast am I traveling

I say that I am traveling at 77 mph and she says I am traveling at 65 mph. Who is correct?

Thank you for your time.
 
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You are correct ... until you bump into the front of the bus.

You can verify this by noting that a car driving 77 mph (your wife can be the driver) passing the bus will be appear stationary for you.

This is Galileo's relativity in action.
 
laytonsdad said:
I say that I am traveling at 77 mph and she says I am traveling at 65 mph. Who is correct?
How fast you are traveling only makes sense if you specify how fast relative to what. Relative to the road, you'd be traveling at 77 mph. Relative to the bus, you'd be traveling at 12 mph. Not sure what your wife had in mind with 65 mph. (Relative to someone running alongside the bus at 12 mph, you'd be traveling at 65 mph.)

Short answer: You are correct.
 
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Thank you for the fast response(s).
 
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Man I hope we didn't ruin the atmosphere at home for you :-)
 
Neither, though you are much closer then she is. Your true speed is about 8.46 billionths of an inch less then 77 miles per hour, due to relativistic effects.
 
mrspeedybob said:
Neither, though you are much closer then she is. Your true speed is about 8.46 billionths of an inch less then 77 miles per hour, due to relativistic effects.

Nitpicker :smile:
 
If we are nitpicking, how much is 77 miles per hour - 8.46 . 10-9 inch? Can I eat that?
 
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