Understanding Time Dilation in GPS and Special Relativity

[mogsy182]

[SOLVED] GPS and special relativity

Homework Statement

time dilation of gps receivers and satellites

Homework Equations

\Delta\tau = \gamma\Delta t

The Attempt at a Solution

so its a part of my project, my tutor has worked it out as using the above equation and has gotten 7microseconds which is the correcr answer, but i can't seem to get that.
Ive got gamma = 1 somehow so there's no difference. my relativity is at best bad lol, so should i use the lorentz transformations?
V = 3.9 e3 m/s
t = 8.64 s (one day)

I can't see what I am doing wrong or where to go with this.

 

[Kurdt]

If he got an answer of 7 microseconds he probably used the binomial expansion approximation.

T \approx T_0 \left(1+\frac{v^2}{2c^2}\right)

 

[mogsy182]

thanks just got it now, used the expansion and got it.