Marinada '26

[lang=hr] Kiki i Hrki su sami na savršeno sferičnom planetu radijusa $1km$. Planet je otkriven 5.11.2014. i tada mu je dano ime "Marinada". Hrki se nalazi u točki $(0, 1, 0)$ i kreće se ravno prema točki $(1,0,0)$ brzinom $1km\,h^{-1}$. Kiki se nalazi u točki $(0,0,1)$ i kreće se ravno prema točki $(0,0,-1)$. Ako Kiki i Hrki kreću u isto vrijeme, kolikom brzinom se Kiki mora kretati kako bi se putem susreo s Hrkijem u točki $(\frac{\sqrt{2}}{2},\frac{\sqrt{2}}{2}, 0)$? Rezultat izrazite u $km\,h^{-1}$. [/lang] [lang=en] Kiki and Hrki are alone on a perfectly spherical planet of radius $1km$. The planet was discovered on November 5, 2014, and was given the name "Marinada" at that time. Hrki is located at the point $(0, 1, 0)$ and moves straight towards the point $(1,0,0)$ at a speed of $1km\,h^{-1}$. Kiki is located at the point $(0,0,1)$ and moves straight towards the point $(0,0,-1)$. If Kiki and Hrki start at the same time, at what speed must Kiki move in order to meet Hrki along the way at the point $(\frac{\sqrt{2}}{2},\frac{\sqrt{2}}{2}, 0)$? Express the result in $km\,h^{-1}$. [/lang]