# Spec Rel: Changes in gradient between frames

1. Mar 19, 2012

### Totoro Recall

1. The problem statement, all variables and given/known data
Suppose a rod measured in the S frame has a gradient of M.

The S' frame travels at v (along x-axis) relative to S. What is the gradient of the rod in the S' frame?

2. Relevant equations
Lorentz tranformations

3. The attempt at a solution

y'=y

x' = $\gamma$(x-vt)

so that m = y'/$\gamma$(x-vt)

This seems straightforward enough, which is why I'm worried. I'm not used to problems in relativity being this easy. Have I missed anything?