# Homework Help: GPS and special relativity

1. Feb 15, 2008

### mogsy182

[SOLVED] GPS and special relativity

1. The problem statement, all variables and given/known data
time dilation of gps receivers and satellites

2. Relevant equations
$$\Delta\tau$$ = $$\gamma$$$$\Delta$$ t

3. 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 cant seem to get that.
Ive got gamma = 1 somehow so theres 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 cant see what im doing wrong or where to go with this.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Feb 15, 2008

### Kurdt

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

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

3. Feb 15, 2008

### mogsy182

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