Translations:Traveltime for velocity linear with depth/2/en

${\begin{aligned}t&{\rm {=}}\int _{{\theta }_{0}/pa}^{\theta {\rm {/}}pa}{\frac {ds}{v}}{\rm {=}}{\frac {\rm {1}}{a}}\int _{{\theta }_{0}}^{\theta }{\frac {d\theta }{{\rm {\ sin\ }}\theta }}.\end{aligned}}$

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