Time dilation

by Huy
Tags: relativity, time dilation
Huy is offline
May22-12, 07:16 AM
P: 2
1. The problem statement, all variables and given/known data
We observe a spaceship moving away from the earth at a velocity of v = 0.866c. The space ship emits two light signals, the second one 4 seconds (Delta T') after the first one (measured on board). What is the time interval (Delta T) between the arrival of the two light signals on earth?

2. Relevant equations
Time dilation, Lorentz contraction, Lorentz transformation, invariance of space-time

3. The attempt at a solution
I basically applied Lorentz transformation: www.i.imgur.com/ylfOJ.jpg (please copy & paste, I can't include a link in my first ten posts...)
However, using my approach I arrive at Delta T = 14s, whereas the solution says it should be 15s. I hope my writing is readable and I'm sorry I didn't know whether this belongs to intro- or advanced physics, the educational system in my country differs from the U.S.' a lot...

Thanks for any help in advance.
Phys.Org News Partner Science news on Phys.org
Internet co-creator Cerf debunks 'myth' that US runs it
Astronomical forensics uncover planetary disks in Hubble archive
Solar-powered two-seat Sunseeker airplane has progress report
jedishrfu is offline
May22-12, 07:37 AM
P: 2,493
did you factor in that the spaceship has moved further away in four seconds? This would delay the second signal a bit more.
Huy is offline
May22-12, 11:59 AM
P: 2
I'm pretty sure I did, because basically, what I am doing in my solution is applying the Lorentz transformation to the inertial system of the spaceship which is moving away with constant velocity.

Register to reply

Related Discussions
You may see a light wave as relative time, without Lorenz time dilation calculated Special & General Relativity 60
Time Dilation or Mass Dilation Special & General Relativity 4
Gravitational time dilation vs velocity time dilation Special & General Relativity 22
Relating SR time dilation and GR time-passage variation Special & General Relativity 0
Calculating Gravitational Time Dilation in black hole/Future Time Travel Special & General Relativity 5