Spatial Separation in Train and Earth's Frame of Reference

[justinh8]

Physics Relativity Question?

Homework Statement

I need some help with this,
A train moves at a constant velocity of 21 m/s. The end of the train passes a sign at 12 noon and 4 seconds later a conductor starts collecting tickets starting with a passenger sitting 25m from the rear of the train. Another passenger located 55m from the rear of the train reads the newspaper at noon and finishes 42 seconds later. What is the Spatial Separation of these events in the frame of reference of the train and the earth?

Homework Equations

delta x = delta x' + v x delta t

The Attempt at a Solution

What i did was i found the difference of the two events and the difference in the x was 30m. the difference in the time was 38 seconds and once i plugged it in the equation i got 828m. Idk if this is right or wrong nor do i know if this is in the frame of reference of the Earth or the train

 

[justinh8]

anyone want to help?

 

[SammyS]

Homework Statement

I need some help with this,
A train moves at a constant velocity of 21 m/s. The end of the train passes a sign at 12 noon and 4 seconds later a conductor starts collecting tickets starting with a passenger sitting 25m from the rear of the train. Another passenger located 55m from the rear of the train reads the newspaper at noon and finishes 42 seconds later. What is the Spatial Separation of these events in the frame of reference of the train and the earth?

Homework Equations

delta x = delta x' + v x delta t

The Attempt at a Solution

What i did was i found the difference of the two events and the difference in the x was 30m. the difference in the time was 38 seconds and once i plugged it in the equation i got 828m. Idk if this is right or wrong nor do i know if this is in the frame of reference of the Earth or the train

anyone want to help?

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You managed to wait all of 81 minutes.

 

[SammyS]

A train moves at a constant velocity of 21 m/s. The end of the train passes a sign at 12 noon and 4 seconds later a conductor starts collecting tickets starting with a passenger sitting 25m from the rear of the train. Another passenger located 55m from the rear of the train reads the newspaper at noon and finishes 42 seconds later. What is the Spatial Separation of these events in the frame of reference of the train and the earth?

delta x = delta x' + v x delta t

What i did was i found the difference of the two events and the difference in the x was 30m. the difference in the time was 38 seconds and once i plugged it in the equation i got 828m. Idk if this is right or wrong nor do i know if this is in the frame of reference of the Earth or the train

My first question is: What events is it asking about? There are at least three.

At 12:00:04, the conductor collects a ticket from passenger A, who is sitting 25m from the rear of the train.

At 12:00:00 a passenger B, who is 55m from the rear of the train, begins reading the newspaper.

At 12:00:42 the passenger B finishes reading the newspaper.​

Other possible events include:

Passenger A passing by the sign.

Passenger B passing by the sign.

The rear of the train passes by the sign.

We could also count the entire 42 seconds worth of passenger B reading the paper. If so, that event may span more than a single point in space, depending upon the frame of reference.
​

The spatial separation of most of these events, in the reference frame of the train is pretty obvious.

By what distance are they separated in the frame of reference of the Earth ?

 

[justinh8]

Ya, i think were not taking about the event of the women that was 25 m from the rear so i think you can just erase that part (my teacher cleared it up) so in reference to the earth, would it just be delta x = 0 + 21(42)? that would be my guess but I am not sure. and if it was reference to the bus, it would be just zero right?

 

[SammyS]

Ya, i think were not taking about the event of the women that was 25 m from the rear so i think you can just erase that part (my teacher cleared it up) so in reference to the earth, would it just be delta x = 0 + 21(42)? that would be my guess but I am not sure. and if it was reference to the bus, it would be just zero right?

What bus ?