Proving No Length Contraction in Lorentz Transformation

[wam_mi]

Homework Statement

Hello,

Consider a rod of proper length l_{0}. Prove/Show that there is no length contraction if an observer moves perpendicular to the direction of the rod.

Homework Equations

l = l_{0}/\gamma

where \gamma is the usual relativistic vector

The Attempt at a Solution

 

[thebigstar25]

please show your attempt first ..