Calculating Train Speeds Using Classical Relativity

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In summary, the conversation discusses the concept of Galilean transformation equations and how different observers would perceive the speed of a westbound train and an eastbound train. It is stated that according to classical relativity, the speed of the eastbound train with respect to the westbound train would be 1.4c. However, there is some confusion regarding the speed of the ticket collector and her perception of the trains' speeds. Overall, the conversation highlights the differences in perception based on different observers and the concept of relative speeds in classical relativity.
  • #1
stunner5000pt
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The classical kind, of course

If two trains leave a station o nteh same track. An observer missed both these trains and is standing clsoe to the track sees the westboun train recede at 0.6c and sees the eastbound train recede at 0.8c. There is a ticket collector on the westbound train going from the back of the train to the front at 0.4c, with respect to a passenger on the westbound train.


If the GALILEAN transformation equations were true then what would the speed of the eastbound train with respect to the westbound train (call it Ur) according to:

A) Observer on the station - i would say 1.4c because that what he sees, right?

b) Passenger seated on the westbound train - 1.4c becasue if he looked behind out hte window he would see the eastbound train go 0.8c + 0.6c away from him

c) Ticket collector on the westbound train (still walking from back to the front) - 1.8c (her speed 0.4c + speed of train 0.6c + speed of east train 0.8c)

Similarly what is the speed of the ticket collector:

d) according to the observer on the station - 1c - speed of the train + TC speed

e) according to passenger seated o tneh east train - 1.8 c


f) relative to a passenger seated on the east train according to to the observer on the station - 1.8c

remember this is using classical relativity, not special relativity, please tell me if i made any mistakes
 
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  • #2
Look at c) again.
 
  • #3
jcsd said:
Look at c) again.
what's wrong with it??

the ticket collector is moving the back of the west train to the front at 0.4c while the train is moving at 0.6c in the same direction if she looekd back then she would see the east train move at train speed + her speed +east train speed, right?

what am i missing here?
 
  • #4
Unless you missed out something in the original question, the question doesn't seem to be asking what speed does the ticket collecter see the train move at.
 
  • #5
What jcsd is saying is that the question specifically asks "what is the speed of the east bound train with respect to the west bound train [\b] accoording to ...

In c, your answer is the speed of the east bound train with respect to the conductor. Using Galilean physics, everyone should say that the speed of the east bound train relative to the west is 0.8c+ 0.6c= 1.4 c.
 
  • #6
HallsofIvy said:
What jcsd is saying is that the question specifically asks "what is the speed of the east bound train with respect to the west bound train [\b] accoording to ...

In c, your answer is the speed of the east bound train with respect to the conductor. Using Galilean physics, everyone should say that the speed of the east bound train relative to the west is 0.8c+ 0.6c= 1.4 c.

so am i right or what?? you just explained my own understanding, and thus if that were true then the collector who is movin at 0.4c westbound would see the speed of her, the train and the east train as the speed of the eastbound train's recedance
 

1. What is the theory of relativity?

The theory of relativity, developed by Albert Einstein, is a set of two theories in physics: the special theory of relativity and the general theory of relativity. These theories explain how the laws of physics work in different frames of reference, and how gravity affects the fabric of space and time.

2. How does the theory of relativity differ from classical physics?

Classical physics, also known as Newtonian physics, describes the laws of motion and gravity for objects at normal speeds and sizes. The theory of relativity, on the other hand, explains the behavior of objects at high speeds and in extreme gravitational fields, where classical physics fails to accurately predict their behavior.

3. What is the principle of relativity?

The principle of relativity states that the laws of physics should be the same for all observers, regardless of their relative motion. This means that the laws of physics are universal and do not depend on the observer's frame of reference.

4. How has the theory of relativity been proven?

The theory of relativity has been extensively tested and proven through various experiments and observations. Some of the most famous evidence includes the bending of starlight by the sun's gravity, the time dilation of moving objects, and the equivalence of mass and energy in Einstein's famous equation, E=mc^2.

5. Why is the theory of relativity important?

The theory of relativity has revolutionized our understanding of the universe and has led to groundbreaking discoveries in physics, such as black holes, gravitational waves, and the expanding universe. It also plays a crucial role in modern technologies, such as GPS systems, which rely on the principles of relativity to function accurately.

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