where a c {\displaystyle a_{c}} is the centripetal acceleration. The direction of the force is toward the center of the circle in which the object is moving, or the osculating circle (the circle that best fits the local path of the object, if the path is not circular).
The assassination of Archduke Franz Ferdinand of Austria, heir presumptive to the Austro-Hungarian throne, and his wife Sophie, Duchess of Hohenberg, occurred on 28 June 1914 in Sarajevo when they were shot dead by Gavrilo Princip.
When the Austrian archduke Franz Ferdinand was shot dead in Sarajevo in June 1914, it triggered a wave of threats, ultimatums and troop mobilisations. By August, Serbia had been invaded by Austria-Hungary and Russia had declared war in response, prompting the German kaiser to declare war on his Russian cousin. A postcard showing a crowd greeting the tsar outside the Winter Palace, August 1914.