Special theory of relativity – problems and solutions
Special theory of relativity – problems and solutions
1. An object whose length is 60 m moves at a speed of 0.6 c (c = the speed of light). According to a stationary observer, what is the length of the object?
Known :
The proper length (Lo) = 60 meters
Object’s speed (v) = 0.6 c
Wanted : The length contraction (L)
c = the speed of light
Lo = the proper length
L = the length contraction
The length contraction (L) :
2. An event observed by a stationary observer for 12 seconds. What is the time interval of the event, according to an observer who moving at a speed of 0.8 c (c = the speed of light).
Known :
The time interval of the event according to a stationary observer (ts) = 12 seconds
The speed of observer (v) = 0.8 c
Wanted: The time interval of the event according to an observer who moving at a speed of 0.8 c (tm)
Solution :
The equation of the time dilation :
ts = the time interval according to a stationary observer
tm = the time interval according to a moving observer
The time interval according to a moving observer (tm) :