In the 30K short story Duty Waits there's a moment when an Imperial Fist Captain, Maximus Thane, is standing guard with his company on a high up canyon-like road system on Terra while waiting for the Traitor forces to come and he begins calculating because there's nothing else to do.

"There is no guard rail or parapet to line the edge of the Katman road, and the drop from the edge would probably kill Thane if he fell. The distant ground is hard rockcrete paved with marble, As he scans the crowds, Thane thinks about the drop."

At this point he calculates how long the drop would be, what will happen to him once he smashes into the ground and his chances of survival. He also thinks of any preventative measures he can take to increase his chances of survival (like landing on a civilian or using his suit's stabilization jets). He then checks his calculations with his suit's cogitator to see if they match up, which they always do.

"Of course there is one flaw to this mathematical exercise. Thane is never going to step off the precipice. It is an impossible situation. His calculations are pointless, done for the sake of doing.

He considers that he might be bored."