Sir , can we choose time t=0 whenever we wish to choose (in the first problem, hospital, Ambulance & person in the car problem, around 19:54 ) like in that problem, we could have choosen time t=0 when 'person in the car' crosses the hospital instead of Ambulance crosses the hospital. And one more question , do we always have to choose some crossing event to be time t=0 OR can we choose t=0 whenever we wish to choose ?? NOTE :: I know that Lorentz transformation is derived on the basis of choosing t=0 when two frames crosses each other . But when multiple frames are involved it is little bit confusing for me that when to choose time t=0 ?? Please clarify. 🙏🙏🙏
@51:43 you found out the distance as 55.4km. I wonder why cant we use lorentz transform. we have respective value of x and t in H frame. why it happens so that lorentz transform doesnt work there?
To apply Lorentz Transformation, you have to be clear about the event. Once you know the co-ordinates and the time of the event, you can apply Lorentz transformation to get co-ordinate and time of that event in another frame. Which event can you define with the problem associated with finding the position of the person at t'=0 in 'A' frame?
shiva1052 Sir is it necessary to have an event in order to use Lorentz transformation. If we have coordinates can't we use it? Suppose we have t=0 and x=48KM, aren't we allowed to use Lorentz transformation to get the respective values in A frame?
Dear Jnan, It is always simple in STR to talk in terms of events, so as not to make a mistake. Let us take your suggestion. To fix our ideas, let us assume that in H frame, there is a building at a distance 48 km and according to H at t=0, the person was in front of that building. Now let us use Lorentz transformation of the event of the man being in front of this building. This transformation would give us the time when the person is in front of the building and the position of this person/ building at that time in A frame. By doing the transformation, we would find that x'=(5/3)x48 km, which is clearly not the correct answer. This is because the time of this event in A frame is not zero. In fact t'=-(5/3)x(.8x48e3/3e8), which is about -2.13e-4 s. Hence what the Lorenz transformation gave us is that at time t'=-2.13e-4 s, the person was in front of the building. Clearly this has not been asked in the problem. What has been asked is the position of the person at t'=0. I hope it is clear.
shiva 1052 ,sir which is the proper time interval wheather in A frame of reference or in persons frame of reference bcoz For doing the calculation for the ambulance we say that the time interval is proper again at 56:48 we say that in persons frame time interval is proper.I m confused plz ans the que or any one plz help
A relativistic particle of mass m and velocity c/2 z^ is moving towards a wall. The wall is moving with velocity c/3 z^ . The velocity of the particle after it suffers a elastic collision is vz^ is equal to a. c/2 b.c/5 c. c/7 d.c/15 . sir please solve this and tell me how these concepts can be used in solving problem s
Shiva1052 sir we take for H ( hospital frame) x=30 km then according P frame of reference ( person frame of reference ) when Person send the signal it's x coordinates must be different because he is moving with relativistic velocity I mean In both frame X must be different in H frame and in P frame
Ya cause the reaching of light signal and ambulance being send are not related with each other,according to the problem it so happens in the H frame that when the signal reached the hospital the ambulance was just crossing the hospital.
Sir , can we choose time t=0 whenever we wish to choose (in the first problem, hospital, Ambulance & person in the car problem, around 19:54 ) like in that problem, we could have choosen time t=0 when 'person in the car' crosses the hospital instead of Ambulance crosses the hospital.
And one more question , do we always have to choose some crossing event to be time t=0 OR can we choose t=0 whenever we wish to choose ??
NOTE :: I know that Lorentz transformation is derived on the basis of choosing t=0 when two frames crosses each other . But when multiple frames are involved it is little bit confusing for me that when to choose time t=0 ?? Please clarify. 🙏🙏🙏
@51:43 you found out the distance as 55.4km. I wonder why cant we use lorentz transform. we have respective value of x and t in H frame. why it happens so that lorentz transform doesnt work there?
To apply Lorentz Transformation, you have to be clear about the event. Once you know the co-ordinates and the time of the event, you can apply Lorentz transformation to get co-ordinate and time of that event in another frame. Which event can you define with the problem associated with finding the position of the person at t'=0 in 'A' frame?
shiva1052 Sir is it necessary to have an event in order to use Lorentz transformation. If we have coordinates can't we use it? Suppose we have t=0 and x=48KM, aren't we allowed to use Lorentz transformation to get the respective values in A frame?
Dear Jnan, It is always simple in STR to talk in terms of events, so as not to make a mistake. Let us take your suggestion. To fix our ideas, let us assume that in H frame, there is a building at a distance 48 km and according to H at t=0, the person was in front of that building.
Now let us use Lorentz transformation of the event of the man being in front of this building. This transformation would give us the time when the person is in front of the building and the position of this person/ building at that time in A frame. By doing the transformation, we would find that x'=(5/3)x48 km, which is clearly not the correct answer. This is because the time of this event in A frame is not zero. In fact t'=-(5/3)x(.8x48e3/3e8), which is about -2.13e-4 s. Hence what the Lorenz transformation gave us is that at time t'=-2.13e-4 s, the person was in front of the building. Clearly this has not been asked in the problem. What has been asked is the position of the person at t'=0. I hope it is clear.
shiva1052 It's clear now.. Thanks sir
shiva1052 sir it is necessary to take t=0 when A frame and H frame coincide
shiva 1052 ,sir which is the proper time interval wheather in A frame of reference or in persons frame of reference bcoz For doing the calculation for the ambulance we say that the time interval is proper again at 56:48 we say that in persons frame time interval is proper.I m confused plz ans the que or any one plz help
In This Three Event Problem Do We Still Have to Take That origins coincide at t=0 of any two frames
A relativistic particle of mass m and velocity c/2 z^ is moving towards a wall. The wall is moving with velocity c/3 z^ . The velocity of the particle after it suffers a elastic collision is vz^ is equal to a. c/2 b.c/5 c. c/7 d.c/15 . sir please solve this and tell me how these concepts can be used in solving problem s
Shiva1052 sir we take for H ( hospital frame) x=30 km then according P frame of reference ( person frame of reference ) when Person send the signal it's x coordinates must be different because he is moving with relativistic velocity
I mean In both frame X must be different in H frame and in P frame
Shiva 1052 , sir according ambulance frame of reference event 1 occurs ( sick person sending the signal) before the h frame
manish khemnani it is necessary to take t=0 when A frame and P frame coincides
Ya cause the reaching of light signal and ambulance being send are not related with each other,according to the problem it so happens in the H frame that when the signal reached the hospital the ambulance was just crossing the hospital.