Help plz with a special relativity question?

Question

A food package is despatched from a space ship at a speed of 0.4c to a space station, from an observer on the space station the package takes 4.5 light days to arrive at a speed of 0.9c. There is a clock on the package how much time has elapsed in transit as measured by the clock? I am guessing it is something to do with time dilation but I am not sure. Any help plz, thanks in advance

Answer 1

4.5 light days

Answer 2

This is indeed a time dilation problem. Use the equation: -

t(observer) = t(on-board)

...................________

.................√(1 - (v/c)²)

Where 'v' is the velocity of the 'package'.

Substitution of the data gives: -

4.5 days = t(on-board)

.................________

...............√(1 - (0.9)²)

Rearrangement, of the above, gives: -

t(on-board) = 4.5 x √(1 - (0.9)²)

Hence: -

t(on-board) = 1.962 (rounded to 3 DP) light days.

Answer 3

Take a look at wikipedia "time dilation".

I think the on-board clock is faster than the receiver's clock by a factor of sqrt(1 - v^2/c^2)

Answer 4

paul are u doin physical world assignment if so email me maybe we can help each other im strugglin with it too. [e-mail]