2015 exam Relativity Section

[doolster]

Did the relativity section for fun.  The answers I got are

1 C  2 B  3 C  4 A  5 A  6 no answer  7 D  8 A   9 C  10 B  11 B

For question 6 I get v = 0.36c which is not even close to an option.

[Conic]

Here . Using this, we find that



so the answer is D. It seems like D is correct for 5. The observer on the earth would measure the proper time interval between sending and receiving the signal, so an observer on the spacecraft would measure a longer time interval (time dilation). The distance covered by the light in 20.0 ms is 6000 km, so the spaceship is 3000 km form the earth when the light pulse reaches it. If the spaceship was further away, the measured time difference would be more than 20.0 ms.

[doolster]

When I retrieved my 1st year Physics text from its duty as a monitor stand I found out that I forgot the square root in the gamma formula
and the correct answer is 0.5c so option D.

An observer on Earth would get a different time interval to that on S66 or T50.